Profile of human papillomavirus genotypes in breast and oesophageal cancer patients in Pretoria, South Africa

Background. The association between human papillomavirus (HPV) and cervical cancer is well established, and cervical cancer can be prevented through HPV vaccination. Little has been reported on the association between HPV and breast carcinoma (BC) or oesophageal squamous cell carcinoma (OSCC) in Africa. It is possible that use of appropriate HPV vaccines against genotypes responsible for these cancers may also prevent their development. Objectives. To investigate HPV genotype prevalence in BC and OSCC patients in Pretoria, South Africa (SA). Methods. A retrospective cross‐sectional study of BC and OSCC patients managed at Steve Biko Academic Hospital from 2015 to 2019 was undertaken. Patient medical records were analysed, and DNA was extracted from their archived pathology material and amplified by polymerase chain reaction before hybridisation for HPV genotypes. Results. There were 101 patients with BC and 50 with OSCC. The prevalence of HPV infection in BC patients was 77.2%, with 35.6% high‐ risk (HR) genotypes, and that in OSCC patients 90.0%, with 56.0% HR genotypes. The most prevalent HPV genotypes (>20% each) were HPV 16, 70 and 51 for BC and HPV 51, 70, 16 and 82 for OSCC, with 31.7% and 60.0% of patients, respectively, having co‐infection with ≥2 genotypes. Conclusion. The high prevalence of infection with multiple HPV genotypes in BC and OSCC patients, with HPV 16, 51, 70, 35 and 82 the most common genotypes in these cancers, warrants expansion of the current SA bivalent HPV 16/18 vaccine for girls to include boys, and inclusion of HPV 51, 70, 35 and 82, in order to prevent BC and OSCC as well as cervical cancer

A Comparative Study on the Dissolution of <i>Argema mimosae</i> Silk Fibroin and Fabrication of Films and Nanofibers

Limited studies have been done on silk fibroins of wild silkworm species owing to their relative insolubility in many solvents. In this study, the solubility of Argema mimosae wild silk fibroin in different salts (LiBr, LiCl, Ca(NO3)2, and CaCl2) dissolved in formic acid under varying temperatures was investigated. The dissolution conditions under which the solubility was optimum were optimized using a central composite design approach. The optimum range for solvation of the fibroin were visualized using contour plots. The influence of temperature and salt concentration were found to significantly influence the solvation of the fibroin. Following the successful dissolution of the fibroin, the regenerated silk fibroin solutions were cast to obtain water insoluble films which were used in investigating optimum electrospinning conditions. Average nanofiber diameters in the 110–141 nm range were obtained under optimum electrospinning conditions. The silk forms were characterized using the FTIR, TGA, XRD, and SEM to understand their properties. The investigations revealed that formic acid—salt solvents were effective in the solvation of the wild silk fibroin. Some of the dissolution conditions induced mild effects on the silk fibroin while others were harsh. Furthermore, processing to nanofibers resulted in the degradation of the β-sheets producing nanofibers rich in α-helices. However, post-treatment using methanol and water vapor were effective in restoring β-sheet crystallinity