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The aim of this study was to explore the relation between self-regulation, psychopathology and gender amongst a group of South African university students (N=384). Self-regulation was measured with the Shortened Self-Regulation Questionnaire (SSRQ: Carey, Neal, & Collins, 2004), and psychopathology with the General Health Questionnaire (GHQ: Goldberg & Hiller, 1979) as well as with an alcohol- and eating risk questionnaire. Results: A negative association was found between self-regulation and psychopathology, but significantly stronger for male students. Self-regulation was found to be more important to males regarding alcohol use and to females regarding eating behaviour. Gender differences in the relationship between self-regulation and psychopathology are probably due to differences in the tendency to rely on self or others, as well as to differences in socio-cultural and control mechanisms regarding alcohol and eating behaviour. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to synthesise and determine the transdermal penetration of cytarabine alkylamide derivatives and assess the correlation of flux with physicochemical properties. Methods The alkylamide derivatives of cytarabine were synthesised by acylation at the N4-amino group by the mixed anhydride method. The in-vitro permeation studies were performed using the Franz diffusion cell methodology. Furthermore, partition coefficients ( n-octanol-water) and aqueous solubility of the N4-alkylamide derivatives of cytarabine were determined in order to obtain information about their lipophilicity and hydrophilicity. Key findings The N4-alkylamides of cytarabine (acetyl, butanoyl, hexanoyl, octanoyl, and decanoyl derivatives) showed decreased hydrophilicity and increased lipophilicity. The log D values of the alkylamides were higher than that of the parent compound and increased linearly as the alkyl chain lengthened. N4-hexanoyl-4-amino-1-[(2R,3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl] pyrimidin-2-one) showed the highest median steady-state flux (Jss) of 89.0 nmol/cm2 per h in the series, which shows a high statistical difference with the parent compound flux value (3.70 nmol/cm2 per h). Conclusions The prodrug approach appears to be a promising strategy for the enhancement of transdermal penetration of cytarabine. [ABSTRACT FROM AUTHOR]

Greening disease of citrus is a serious disease known in South Africa since the late 1920s. In South Africa, it is associated with infection by 'Candidatus Liberibacter africanus', a heat sensitive, phloem-limited, noncultured alpha-proteobacterium. Huanglongbing (HLB), a similar, but more devastating disease that was described initially from China but which now occurs in several citrus producing countries, is associated with a different Liberibacter species, 'Ca. L. asiaticus'. A 'Ca. L. africanus' subspecies, 'Ca. L. africanus subsp. capensis', has been found only in South Africa infecting an indigenous Rutaceous species, Calodendrum capense (Cape Chestnut), in the Western Cape in 1995. The discovery of a new Liberibacter species in Brazil, 'Ca. L. americanus', and the spread of 'Ca. L. asiaticus' to a number of additional countries over the last few yeass prompted us to assess whether only 'Ca. L. africanus' is present in commercial citrus orchards in South Africa. Samples displaying greening or similar symptoms were collected from 249 citrus trees from 57 orchards distributed throughout the greening affected citrus production areas of South Africa. Multiplex polymerase chain reaction (PCR) was performed on DNA extracts to detect the known citrus Liberibacters. Amplicons were obtained from 197 samples. None of the samples yielded a 1,027-bp amplicon indicative of 'Ca. L. americanus' infection. The amplicons of 84 samples were sequenced, and all were identical to the cognate 'Ca. L. africanus' Nelspi-uit sequence in GenBank. No instance of 'Ca. L. asiaticus' or 'Ca. L. africanus subsp. capensis' sequence was found. Geographically representative samples that tested negative for Liberibacter also tested negative for phytoplasmas based on real-time PCR results. Based on the results of this survey, it is concluded that to date only 'Ca. L. africanus' is associated with citrus greening in commercial citrus in South Africa. [ABSTRACT FROM AUTHOR]

Objective: This study was conducted to determine the prevalence of hazardous, harmful and dependent drinking among hostel-dwelling students on the main campus of the University of the Free State (UFS), and the influence of sex and academic year on the habit., Method: A quarter of all hostel-dwelling students of UFS were selected by systematic random sampling. Willing participants completed a questionnaire comprising a demographic section and the Alcohol Use Disorders Identification Test (AUDIT)., Results: Of the 339 participants with total AUDIT scores, 15.6% exhibited hazardous drinking, 4.1% harmful drinking and 5.6% alcohol dependence. Male students had a statistically significant higher prevalence (32.8%) of hazardous, harmful or dependent drinking than female students (18.9%). Women, however, are biologically more vulnerable to the ill effects of alcohol due to altered pharmacokinetics and pharmacodynamics of alcohol. In addition, intoxicated women suffer more biological and social risks. When the cut-off point for hazardous drinking was adapted to account for the increased biological vulnerability of women, the difference between female and male participants was no longer significant. First year male students were less likely to engage in unsafe drinking than senior students. Female students in the alcohol dependent category showed an increasing trend over advancing academic year., Conclusions: Follow-up studies are needed to confirm whether a significant difference in hazardous drinking of first year male students compared to seniors reflects the influence of university policy or merely precedes drinking acculturation.

Citrus Viroid IV or Bark cracking viroid (CVd-IV) has been reported from various countries, mostly in the Near East, but was unknown in southern Africa. It can cause severe bark cracking of trifoliate orange (Poncirus trifoliata), but symptoms on the indicator, Arizona 861-S-1 Etrog (Citrus medica), are mild and transient, usually leaf epinasty (2-4). CVd-IV was detected for the first time in South Africa during the 2009 biennial indexing of mother trees maintained for the South African Citrus Improvement Scheme (CIS). Symptoms were observed on Etrog indicators budded with material from mother trees of DuRoi Valencia sweet orange (C. sinensis). Initially, leaf bend of a single leaf was noted on one plant, and later, petiole browning developed on all test plants. Reverse transcription (RT)-PCR testing confirmed CVd-IV infection by amplification of a 286-bp PCR product representing the full-length CVd genome using the primers CVd-IV-F3 5'-GGTGGATACAACTCTTGGG-3' (1) and CVd-IV-SL3 5'-GGGTAGTTTCTATCTCAG-3' (N. Duran-Vila personal communication). Samples of 78 field and 30 nursery trees of DuRoi Valencia supplied over a 7-year period from the CIS were budded on Etrog and tested 3 months after inoculation. Ninety positive samples were obtained from trees up to 7 years old. These trees were on either Swingle citrumelo (P. trifoliata × C. paradisi) or rough lemon (C. jambhiri) rootstocks and no symptoms of bark-cracking or other abnormalities were noted on these trees. Following the initial interception, a comprehensive screening of the CIS gene source, consisting of 450 cultivars, was initiated and CVd-IV was detected in five other accessions: SB navel (C. sinensis) collected in 1984 in Kwa-Zulu Natal Province of South Africa, Gillemberg navel (C. sinensis) collected in 1986 in Limpopo Province, Tarocco midseason (C. sinensis) imported from Sicily in 1987, Fortuna mandarin (C. reticulata) imported from Spain in 1987, and Westin midseason (C. sinensis) imported from Brazil in 1994. None of these accessions are planted on a commercial scale and field observations are therefore not possible. PCR amplicons of all positive samples were bidirectionally sequenced and sequences submitted to GenBank. Sequence comparisons showed those obtained from DuRoi Valencia (JN903763), Tarocco (JN903764), and SB Navel (JN903765), and GenBank reference sequences AB054633 (Japan) and HM042747 (China) to be identical. Likewise, the South African sequences from Westin (JN903766) and Gillemberg (JN903767) were identical to reference sequences X14638 and NC_003539 (Israel) and GQ260216 (Iran). The Fortuna sequence (JN903762) differed by two base pairs from the latter group. On the basis of the entry dates of the accessions, it is probable that CVd-IV has been in South Africa since at least 1984, but was not detected during indexing because of the erratic symptom expression of CVd-IV on Etrog. Existing CVd-IV-contaminated field material will be monitored for possible disease expression, but thus far the trifoliate hybrid and rough lemon rootstocks do not show the same susceptibility as reported for P. trifoliata (4). The detection of CVd-IV in field and gene-source material emphasizes the importance of intensive and specific indexing to ensure distribution of pathogen-free citrus in South Africa. References: (1) L. Bernad and N. Duran-Vila. Mol. Cell. Probes 20:105, 2006. (2) N. Duran Vila et al. J. Gen. Virol. 69:3069, 1988. (3) H. Putcha et al. Nucleic Acids Res. 19:6640, 1991. (4) C. Vernière et al. Plant. Dis. 88:1189, 2004.

The objective of this study was to determine the in vitro transdermal permeation through the human stratum corneum (SC) of the antiretroviral (ARV) drug lamivudine (3TC) (1) and its synthesised methoxypoly(ethylene glycol) (MPEG) carbamates and carbonates in phosphate buffer solution and with the use of Pheroid as delivery system and to establish a relationship, if any, with selected physicochemical properties. The synthesis and in vitro human skin permeation flux of three N4-methoxypoly(ethylene glycol) carbamates (3)-(5) and three 6'-O-methoxypoly(ethylene glycol) carbonates (6)-(8) of lamivudine are reported. The derivatives were synthesised in a two-step process by coupling activated MPEG oligomers of various chain lengths to either the 4-amino or 6'-hydroxy group of lamivudine. Irrespective of the oligomeric series of derivatives (carbamate or carbonate), the aqueous solubility increases as the MPEG chain lengthens while the solubility in octanol (lipophilicity) remained almost constant. Regardless of the mechanism of diffusion viz. passive (in PBS) or use of enhancer (Pheroid), no derivative penetrate the skin better than the parent drug itself. The use of Pheroid even appeared to significantly retard the skin permeation.

The purpose of this study was to synthesize and determine the in vitro transdermal penetration of cytarabine and its 5'-alkyl esters and to establish a correlation, if any, with selected physicochemical properties. The n-alkyl esters were synthesized by acylation of cytarabine (1) at its pharmacophoric 5'-OH. The transdermal flux values of (1) and its esters were determined in vitro using Franz diffusion cell methodology. Aqueous solubility and log D (pH 7.4) values were determined and assessed for correlation to transdermal flux. An inverse relation was observed between the water solubility (Sw) and log D values. Of all esters, (4) exhibited the highest flux value of 22.2 nmol x cm(-2) x h(-1), which is significantly different to that of the parent drug cytarabine (3.70 nmol x cm(-)2 x h(-1)). No trend was found between water solubility and flux values.

In continuation of studies focusing on the transdermal delivery of antiretroviral (ARV) drugs, the skin permeation ability of synthesized homologous series of both oligomeric and polymeric ethylene glycol (PEG) carbonates of zidovudine (3'-azido-3'-deoxythymidine, AZT, CAS 30516-87-1) and stavudine (2',3'-dideoxy-2',3'-didehydrothymine, d4T, CAS 3056-17-5) was evaluated in vitro through excised human skin in phosphate buffered solution (PBS) (0.01 M, pH 7.4) at 37 degrees C by using Franz cell diffusion methodology. The results revealed that all the derivatives permeated the skin regardless of the series. However, the derivative having three ethylene glycol repeating units was the most effective permeant in each series. The skin permeation rates of zidovudine and stavudine were enhanced by factors in the 2-4, and 1-3 range through these carbonates, respectively.

The objective of this study was to synthesize derivatives of the anti-HIV drug stavudine (d4T) with more favourable physicochemical properties for transdermal delivery in an effort to increase transdermal penetration of stavudine and thus reduce the severe side effects associated with the dose-dependent oral therapy. The synthesis, hydrolytic stability, and in vitro human skin permeation flux of a series of novel methoxypoly(ethylene glycol) (MPEG) carbonates of stavudine are reported. The carbonates were synthesized in a two-step process by coupling the MPEG promoiety of various chain lengths to C-5' of d4T. In kinetic studies the carbonates proved to be markedly stable in weakly acidic phosphate medium (pH 5.0) with half-lives ranging from 16 to 58 days. The aqueous solubility increased as the ethylene oxide chain lengthened. However, there was no significant increase in the estimated solubility in octanol. In vitro in the phosphate buffer (200 mM; pH 5.0) almost all carbonates permeate the human skin. However, the most effective penetrant, the derivative with 3 ethylene oxide units in the side chain, exhibited a flux of 26.1 nmol/cm(2)/h as compared to 59.15 nmol/cm(2)/h of the parent drug stavudine. Thus, no permeation enhancement was observed during this study.

Advantages associated with the transdermal delivery route are well documented, but in the past scientists have concentrated primarily on means of decreasing the barrier function of the skin for improved permeability. Pro-drugs, which possess more favourable physicochemical properties for improved transdermal permeability may have considerable potential. These have been considered in the past but recent information concerning structure activity relationships in dermal penetration has prompted increased interest. During this study, N-methyl (2), N-ethyl (3) and N-(2-hydroxyethyl) carbamazepine (4) analogues were synthesised for transdermal evaluation.

The in vitro antimalarial activity of a series of 2- and 8-trifluoromethyl- and 2,8-bis(trifluoromethyl)quinoline-4-(5-pyrimidino) and N4-ethyl-5-nitroimidazolo)methylene ketones was assessed against the chloroquine-sensitive strain (D10) of Plasmodium falciparum. Although the in vitro antimalarial activity of these compounds is more or less of the same order of magnitude, derivatives containing two trifluoromethyl groups achieve a slightly higher in vitro activity than compounds with one trifluoromethyl group, with 2,8-bis(trifluoromethyl) quinoline-4-(N4-ethyl-5-nitroimidazolo) methylene and 2,8-bis(trifluoromethyl) quinoline-4-(5-pyrimidino) ketones showing IC50 of 4.8 and 5.2 micrograms/ml, respectively. These compounds seem to bind to DNA by intercalation.

A range of N-substituted isoindolin-1-ones was prepared and their potential as novel antimicrobial agents was investigated. MIC values for active compounds were determined and reported.

The solubility of chlorthalidone in 16 solvent systems was determined in the absence and presence of different amounts of beta-cyclodextrin (beta-CD). Chlorthalidone (CT) was shown to be more soluble in hydrophilic organic solvents, with the highest solubility in ethylacetate (EtOAc) saturated with water. The solubility of CT in water, butanol, octanol, and dichloromethane (DCM) was enhanced by the addition of beta-cyclodextrin. The enantioselective partitioning of CT between water and EtOAc, DCM, butan-1-ol, butan-2-ol, and octan-1-ol was determined in the presence of beta-CD at pH 5, 7, and 9. According to the results, both the solubility and partitioning properties of CT are affected by beta-CD in aqueous solution. It was also shown that the solubility of the individual enantiomers differs in the presence of beta-CD.

Trimethoprim undergoes thermally and photochemically catalyzed hydrolysis or oxidation to give rise to at least five products. The structures of these compounds were determined by physical methods and it was found that the resonance of C-5 in the 13C NMR spectrum is indicative of the substitution pattern of the resultant amino hydroxy pyrimidines.