The role of crude saliva and purified salivary mucins in the inhibition of the Human Immunodeficiency Virus type 1

BACKGROUND:Sub-Saharan Africa is the world's worst HIV-AIDS affected region. More interventions to manage this pandemic are urgently required. Transmission of the virus through an exchange of saliva is rarely known to occur. This project sought to verify statistically previous findings in our laboratory, that crude saliva from uninfected individuals together with its purified mucin components inhibited HIV-1, whilst mucins from infected saliva did not show this inhibition, in an in vitro assay. METHODS: Saliva was extracted in 4M guanidinium hydrochloride and proteolytic inhibitors at pH 6.5, followed by the isolation of MUC5B and MUC7 by Sepharose 4B gel filtration and further purification of these mucins by density-gradient ultra-centrifugation in caesium chloride. Agarose gel electrophoresis, Western blotting and amino acid compositional analysis determined the size, purity and identity of the mucins. The inhibitory activity of crude saliva and purified MUC5B and MUC7, from HIV negative (n=20) and HIV positive (n=20) donors, was tested by their incubation with subtype C HIV-1 and subsequent infection of peripheral blood mononuclear cells (PBMCs). PCR was done on tandem repeat regions of MUC5B and MUC7 DNA to investigate whether any association existed between gene polymorphism and susceptibility to infection. RESULTS: There was an inter-individual variation in the amounts of MUC5B and MUC7 in saliva. In contrast to previous studies, crude saliva and purified mucins from both HIV negative and HIV positive individuals inhibited the infection of HIV-1 in an in vitro assay. DNA analysis of the tandem repeat regions of MUC5B and MUC7 revealed no difference between groups. CONCLUSIONS: Crude saliva and its mucins, MUC5B and MUC7, from both uninfected controls and HIV positive individuals inhibited HIV-1 in an in vitro assay

Placement, support, and retention of health professionals: national, cross-sectional findings from medical and dental community service officers in South Africa

Background: In South Africa, community service following medical training serves as a mechanism for equitable distribution of health professionals and their professional development. Community service officers are required to contribute a year towards serving in a public health facility while receiving supervision and remuneration. Although the South African community service programme has been in effect since 1998, little is known about how placement and practical support occur, or how community service may impact future retention of health professionals. Methods: National, cross-sectional data were collected from community service officers who served during 2009 using a structured self-report questionnaire. A Supervision Satisfaction Scale (SSS) was created by summing scores of five questions rated on a three-point Likert scale (orientation, clinical advising, ongoing mentorship, accessibility of clinic leadership, and handling of community service officers’ concerns). Research endpoints were guided by community service programmatic goals and analysed as dichotomous outcomes. Bivariate and multivariate logistical regressions were conducted using Stata 12. Results: The sample population comprised 685 doctors and dentists (response rate 44%). Rural placement was more likely among unmarried, male, and black practitioners. Rates of self-reported professional development were high (470 out of 539 responses; 87%). Participants with higher scores on the SSS were more likely to report professional development. Although few participants planned to continue work in rural, underserved communities (n = 171 out of 657 responses, 25%), those serving in a rural facility during the community service year had higher intentions of continuing rural work. Those reporting professional development during the community service year were twice as likely to report intentions to remain in rural, underserved communities. Conclusions: Despite challenges in equitable distribution of practitioners, participant satisfaction with the compulsory community service programme appears to be high among those who responded to a 2009 questionnaire. These data offer a starting point for designing programmes and policies that better meet the health needs of the South African population through more appropriate human resource management. An emphasis on professional development and supervision is crucial if South Africa is to build practitioner skills, equitably distribute health professionals, and retain the medical workforce in rural, underserved areas

Developing a tool to assess the skills to perform a health technology assessment.

BACKGROUND: Health technology assessment (HTA) brings together evidence from various disciplines while using explicit methods to assess the value of health technologies. In resource-constrained settings, there is a growing demand to measure and develop specialist skills, including those for HTA, to aid the implementation of Universal Healthcare Coverage. The purpose of this study was twofold: a) to find validated tools for the assessment of the technical capacity to conduct a HTA, and if none were found, to develop a tool, and b) to describe experiences of its pilot. METHODS: First, a mapping review identified tools to assess the skills to conduct a HTA. A medical librarian conducted a comprehensive search in four databases (MEDLINE, Embase, Web of Science, ERIC). Then, incorporating results from the mapping and following an iterative process involving stakeholders and experts, we developed a HTA skills assessment tool. Finally, using an online platform to gather and analyse responses, in collaboration with our institutional partner, we piloted the tool in Ghana, and sought feedback on their experiences. RESULTS: The database search yielded 3871 records; fifteen those were selected based on a priori criteria. These records were published between 2003 and 2018, but none covered all technical skills to conduct a HTA. In the absence of an instrument meeting our needs, we developed a HTA skill assessment tool containing four sections (general information, core and soft skills, and future needs). The tool was designed to be administered to a broad range of individuals who would potentially contribute to the planning, delivery and evaluation of HTA. The tool was piloted with twenty-three individuals who completed the skills assessment and shared their initial impressions of the tool. CONCLUSIONS: To our knowledge, this is the first comprehensive tool enabling the assessment of technical skills to conduct a HTA. This tool allows teams to understand where their individual strengths and weakness lie. The tool is in the early validation phases and further testing is needed. TRIAL REGISTRATION: Not applicable

The role of crude saliva and purified salivary mucins in the inhibition of the Human Immunodeficiency Virus type 1

Includes bibliographical references.Sub- Saharan Africa is the world's worst HIV-AIDS affected region. More interventions to manage this pandemic are urgently required. Transmission of the virus through an exchange of saliva is rarely known to occur. The role of saliva and its mucus in this inhibition requires clarification. This project sought to verify the previous findings in our laboratory (Habte et al. , 2006; Peacocked et al. (manuscript under revision)), that crude saliva from uninfected individuals together with its purified mucin components inhibited HIV-1 in an in vitro assay. Mucins from infected saliva did not show inhibition in this assay. Mucus was extracted in 6M guanidinium hydrochloride and a cocktail of protease inhibitors, pH 6.5. Sepharose CL-4B gel filtration separated MUC5B and MUC7 in saliva. Mucins were purified by density gradient ultra-centrifugation in caesium chloride. Western blotting and amino acid analysis determined the size, charge and identity of the mucins. The inhibitory activity of crude saliva, salivary mucin components MUC5B and MUC7 from HIV-negative and HIV-positive donors, was tested by their incubation in an in vitro HIV-neutralisation assay using a pseudovirus of Subtypes A and C, and infection of susceptible epithelial tumour cells (genetically modified TZM- bl cells). Glycosylation analysis by HPLC was also performed on each group. The presence of MUC5B and MUC7 in saliva was confirmed and it was shown that there was inter-individual variation in their amounts and electrophoretic behaviour between and within groups. Crude HIV-negative and HIV-positive saliva and its purified mucins MUC5B and MUC7 significantly inhibited the infection of HIV-1 in an in vitro pseudoviral assay in a dose-response manner. HPLC revealed two glycoforms of salivary MUC5B

The role of crude saliva and purified salivary mucins in the inhibition of the Human Immunodeficiency Virus type 1

Abstract Background Sub-Saharan Africa is the world’s worst HIV-AIDS affected region. More interventions to manage this pandemic are urgently required. Transmission of the virus through an exchange of saliva is rarely known to occur. This project sought to verify statistically previous findings in our laboratory, that crude saliva from uninfected individuals together with its purified mucin components inhibited HIV-1, whilst mucins from infected saliva did not show this inhibition, in an in vitro assay. Methods Saliva was extracted in 4 M guanidinium hydrochloride and proteolytic inhibitors at pH 6.5, followed by the isolation of MUC5B and MUC7 by Sepharose 4B gel filtration and further purification of these mucins by density-gradient ultra-centrifugation in caesium chloride. Agarose gel electrophoresis, Western blotting and amino acid compositional analysis determined the size, purity and identity of the mucins. The inhibitory activity of crude saliva and purified MUC5B and MUC7, from HIV negative (n=20) and HIV positive (n=20) donors, was tested by their incubation with subtype C HIV-1 and subsequent infection of peripheral blood mononuclear cells (PBMCs). PCR was done on tandem repeat regions of MUC5B and MUC7 DNA to investigate whether any association existed between gene polymorphism and susceptibility to infection. Results There was an inter-individual variation in the amounts of MUC5B and MUC7 in saliva. In contrast to previous studies, crude saliva and purified mucins from both HIV negative and HIV positive individuals inhibited the infection of HIV-1 in an in vitro assay. DNA analysis of the tandem repeat regions of MUC5B and MUC7 revealed no difference between groups. Conclusions Crude saliva and its mucins, MUC5B and MUC7, from both uninfected controls and HIV positive individuals inhibited HIV-1 in an in vitro assay.</p

Mucus and Mucins: do they have a role in the inhibition of the human immunodeficiency virus?

Background: Mucins are large O-linked glycosylated proteins which give mucus their gel-forming properties. There are indications that mucus and mucins in saliva, breast milk and in the cervical plug inhibit the human immunodeficiency virus (HIV-1) in an in vitro assay. Main body of abstract: Crude mucus gels form continuous layers on the epithelial surfaces of the major internal tracts of the body and protect these epithelial surfaces against aggressive luminal factors such as hydrochloric acid and pepsin proteolysis in the stomach lumen, the movement of hard faecal pellets in the colon at high pressure, the effects of shear against the vaginal epithelium during intercourse and the presence of foreign substances in the respiratory airways. Tumour-associated epitopes on mucins make them suitable as immune-targets on malignant epithelial cells, rendering mucins important as diagnostic and prognostic markers for various diseases, even influencing the design of mucin-based vaccines. Sub-Saharan Africa has the highest prevalence of HIV-AIDS in the world. The main points of viral transmission are via the vaginal epithelium during sexual intercourse and mother-to-child transmission during breast-feeding. There have been many studies showing that several body fluids have components that prevent the transmission of HIV-1 from infected to non-infected persons through various forms of contact. Crude saliva and its purified mucins, MUC5B and MUC7, and the purified mucins from breast milk, MUC1 and MUC4 and pregnancy plug cervical mucus (MUC2, MUC5AC, MUC5B and MUC6), inhibit HIV-1 in an in vitro assay. There are conflicting reports of whether crude breast-milk inhibits HIV-1 in an in vitro assay. However studies with a humanised BLT mouse show that breast-milk does inhibit HIV and that breast-feeding is still advisable even amongst HIV-positive women in under-resourced areas, preferably in conjunction with anti-retroviral treatment. Conclusion: These findings raise questions of how such a naturally occurring biological substance such as mucus, with remarkable protective properties of epithelial surfaces against aggressive luminal factors in delicate locations, could be used as a tool in the fight against HIV-AIDS, which has reached epidemic proportions in sub-Saharan Africa