Trends in diabetes research outputs in South Africa over 30 years from 2010 to 2019: A bibliometric analysis

Diabetes mellitus (DM) is one of the leading causes of mortality in South Africa, which is impelled by people’s consumption of unhealthy diets and lifestyles, negligence about an individual’s health status, and increased urbanization. DM can be linked to several human diseases and thus, making it an important public health issue in the South African health sector. Therefore, it is necessary to assess the level of research that has been conducted in the country on diabetes, in a quest for solutions against the deadly disease. Hence, the present study aimed to map diabetes-related research in South Africa from 2010 to 2019. Data on the subject was retrieved from the Web of Science Core Collection (WoSCC) and bibliometrix package in Rstudio statistical software was used to analyze the data while VOSviewer was explored for data visualization networks. Our analysis revealed that the annual growth rate of publication trends was 23.2%. The authors per document were 23.3 with a collaboration index of 23.4. From the 416 articles analyzed, Islam MS (n = 34) was the most prolific author and the top active institution was University of KwaZulu-Natal (n = 165) and the top journal was Diabetes Research and Clinical Practice (n = 20). Findings from this study reveal that the quantity of research on diabetes has significantly increased over the decade, and the outcomes of this scientific progress can guide future research and substantially provide the basic needs for improving management procedures for diabetes in the country.     

The impact of blood and seminal plasma zinc and copper concentrations on spermogram and hormonal changes in infertile Nigerian men

Zinc (Zn) and copper (Cu) concentrations in sera and seminal plasma of 60 infertile males (40 oligozoospermic and 20 azoospermic) and 40 males with evidence of fertility (normozoospermic; controls) were estimated using atomic absorption spectrophotometry. The results were correlated with the subject's spermogram and hormonal levels in order to determine their relationship and significance in male infertility. The mean serum concentration of zinc was significantly (p<0.01) higher in oligozoospermic males when compared to azoospermic subjects and controls. The ratios of serum Zn to seminal plasma Zn were 1:1, 1:3 or 1:4 in oligozoospermic, normozoospermic or azoospermic subjects, respectively. While the mean Cu concentration was significantly higher in serum than seminal plasma in all groups, the Zn concentration was significantly (p<0.05) higher in seminal plasma than serum. The Cu/Zn ratio in seminal plasma was significantly (p<0.01) higher in controls compared with other groups. A significant (p<0.01) inverse correlation was observed between serum Zn and sperm counts. Similarly, seminal plasma Zn negatively correlated with spermatozoa viability. In conclusion, the measurement of serum Zn level, apart from being a good index of the assessment of prostatic secretion and function, may be considered a useful tool in addition to other parameters in assessing male infertility. Also, a lower Cu/Zn ratio in seminal plasma may serve as a supportive tools in assessing male infertility.     

Synthesis of polyglycerol phosphate by Bacillus stearothermophilus.

A particulate enzyme preparation from Bacillus stearothermophilus synthesized 1,3-poly(glycerol phosphage) from CDPglycerol at an optimum pH of 8.0 and the reaction was stimulated by divalent cations. Km for CDPglycerol was 0.18 mM. The synthesis was inhibited by CMP, CDP, and CTP and by concentrations of CDP-glycerol above 0.49 mM. The reaction was irreversible, The product had an average chain length of 8 glycerol units. About two thirds of the polymers were synthesized in entirety while the ramainder were attached to some acceptor by their phosphate end. The enzome was able to synthesize only a limited amount of polymer.     

Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs

Background  

Nitric oxide and prostaglandin E₂ (PGE₂play pivotal roles in both the pathogenesis of osteoarthritis and catabolic processes in articular cartilage. These mediators are influenced by both IL-1β and mechanical loading, and involve alterations in the inducible nitric oxide synthase (iNOS) and cyclo-oxygenase (COX)-2 enzymes. To identify the specific interactions that are activated by both types of stimuli, we examined the effects of dynamic compression on levels of expression of iNOS and COX-2 and involvement of the p38 mitogen-activated protein kinase (MAPK) pathway.     

Blood Group Antigens C,Lub and P1 May Have a Role in HIV Infection in Africans

Background

Botswana is among the world’s countries with the highest rates of HIV infection. It is not known whether or not this susceptibility to infection is due to genetic factors in the population. Accumulating evidence, however, points to the role of erythrocytes as potential mediators of infection. We therefore sought to establish the role, if any, of some erythrocyte antigens in HIV infection in a cross-section of the population.

Methods

348 (346 HIV-negative and 2 HIV-positive) samples were obtained from the National Blood Transfusion Service as residual samples, while 194 HIV-positive samples were obtained from the Botswana-Harvard HIV Reference Laboratory. Samples were grouped for twenty three antigens. Chi-square or Fischer Exact analyses were used to compare the frequencies of the antigens in the two groups. A stepwise, binary logistic regression was used to study the interaction of the various antigens in the light of HIV-status.

Results

The Rh antigens C and E were associated with HIV-negative status, while blood group Jk^a, P₁ and Lu^b were associated with HIV-positive status. A stepwise binary logistic regression analysis yielded group C as the most significant protective blood group while Lu^b and P₁ were associated with significantly higher odds ratio in favor of HIV-infection. The lower-risk-associated group C was significantly lower in Africans compared to published data for Caucasians and might partially explain the difference in susceptibility to HIV-1.

Conclusion

The most influential antigen C, which also appears to be protective, is significantly lower in Africans than published data for Caucasians or Asians. On the other hand, there appear to be multiple antigens associated with increased risk that may override the protective role of C. A study of the distribution of these antigens in other populations may shed light on their roles in the HIV pandemic.     

文山松毛虫质型多角体病毒形态结构及理化性质的研究

对文山松毛虫质型多角体病毒的形态结构及理化特性进行了研究,多角体大部分为六边形,少数为四边形及近园形,其大小在0.47～2.45μ之间,平均为1.1μ。病毒粒子呈球形,无囊膜,致密的核芯区由一层外壳包裹,直径为60nm。病毒粒子表面有12个刺突,放大图象可见其亚单位排列。多角体蛋白的主要成分为一种,分子量为26200道尔顿,多角体蛋白氨基酸组成中不含半胱氨酸;其碱性氨基酸与酸性氨基酸之比为1:2.16。病毒粒子结构蛋白含五条多肽组分。用SDS-热酚法提取所得核酸,其热变性紫外吸收OD_(260)值增加51.6％。抗核酸酶S_1。Tm值为86℃。在1％琼脂糖凝胶电泳中可分为9个片段,而在5％PAGE中,则可分为10个片段。各片段大小在0.66×10~6～2.85×10~6道尔顿之间,总分子量为15.35×10~6。电镜分析研究显示了CPV RNA在0.4μ、0.8μ和1.2μ处有三个分布峰。     

An Investigation into the Rate and Control of Assimilate Movement from Leaves in Pisum sativum

Export studies were made on leaves of Pisum by monitoring the¹⁴CO₂-treated source leaf at its surface at frequent intervals.Radiocarbon levels of fresh leaf samples showed a good correlationwith results from the more conventional methods of radiocarbonestimation which involve destructive analysis. The rate of export was highest in plants which had been defoliated,except for the source leaf 20 h or more before the start ofthe export study. Removal of the shoot apex reduced export andprogressive reduction in sink capacity was associated with decreasedexport rates, particularly over short time periods. Export rateswere similar in defoliated and non-defoliated plants where theshoot apex and the roots had been excised. This suggested thata decrease in the source resulted in higher export rates fromthe remaining source only when active sinks were present; thisin turn suggests that, at least under these conditions, activeremoval of photosynthate is more important in controlling exportthan the photosynthate build-up in the leaf itself. The non-destructive technique enabled comparisons to be madebetween export curves for individual plants. It was found thatin experiments replicated in time, the same relationship betweentreatments was present on different days and the shape of theexport curves was similar but the absolute values for exportedradiocarbon sometimes varied considerably.     

Chilling-induced Lipid Hydrolysis in the Oil Palm (Elaeis guineensis) Mesocarp

Oil palm fruits exposed to temperatures of 15 °C and belowshowed a significant increase in free fatty acid (FFA) contentin the mesocarp. This effect was most pronounced in fruits exposedto 5 °C when FFA levels exceeding 70% of the total oil wereobserved. The increase in FFA was accompanied by an increasein lipid-soluble phosphorus levels and a decrease in carotenecontent. Chilling did not have an effect on palm kernel oil.The results suggest the activation of a lipase in the mesocarpby low temperature stress. Key words: Lipase, oil palm, free fatty acid