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An evaluation of the attitudes and understanding of HIV/AIDS that underpins the decision to comply or not comply with prenatal HIV/AIDS testingKenana, Motlatsi Queen January 2007 (has links)
Magister Artium - MA / This study aimed to explore the attitudes to HIV testing among a group of black, low socio-economic status pregnant women from Gugulethu, South Africa. The key research interest was to evaluate the attitudes and understandings of HIV/AIDS that underpin the decision to comply or not comply with prenatal HIV testing. Theories of health behaviour concur that the extent to which an individual will engage in a given health behaviour, such as HIV test compliance, will be a function of the extent to which a person believes she is personally susceptible to the particular illness and her evaluation of the severity of the consequences of contracting the disease. / South Africa
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Stigmatisation of a patient co-infected with TB and HIV / Deliwe René PhetlhuPhetlhu, Deliwe René January 2005 (has links)
The last few years have seen an increase in the infection rate not only of HIV but also TB.
The HIV/AIDS pandemic is increasing rapidly mainly in developing countries with 71 % of
infections in the Sub-Saharan region of Africa. South Africa, which forms part of the Sub-
Saharan region, has the highest infection rate in the world with 3.2 to 3.4 million people
living with HIV/AIDS. People with HIV are especially vulnerable to TB, and HIV pandemic
is fuelling an explosive growth in TB cases. The increase in the infection rate of TB and
HIV exert increased pressure on health service delivery thus reflecting the serious problem
in the country with regard to health service delivery to people co-infected with TB and
HlV/AlDS.
Health service delivery is also hindered by negative attitudes of health workers that have
been reported towards people living with HIV/AIDS. They entertain a biased view of their
own risk, considering risk only from occupational exposure and denying the possibility of
infection in their private life. These attitudes of health workers decreases the quality of
care and support delivered to patient co-infected with TB and HIV. This result in people
not disclosing their illness even in cases were treatment is available like TB for the fear of
stigmatisation. Hence the problem of stigmatisation escalates into a dilemma for the
patient co-infected with TB and HIV. Therefore these patients tend to shy away from
health services and isolate themselves due to fear of being stigmatised twice.
The need to address TB and HIV together in the light of this dimension is urgent so as to
improve the utilization of the health services by people co-infected with Ti3 and HIV. The
purpose of this research was to explore and describe the experiences of patients co-infected
with TB and HIV regarding stigmatisation by the health workers, to explore and
describe the attitudes of health workers towards patients co-infected with TB and HIV, and
to formulate guidelines for health workers that will facilitate the health service utilization by
patients co-infected with TB and HIV in the Potchefstroom district.
The research was conducted in the Potchefstroom district in the North West province of
South Africa. A qualitative research design was used to explore and describe the
experiences of patients co-infected with TB and HIV regarding stigmatisation by the health
workers, and to explore and describe the attitudes of health workers toward co-infected
patients. A purposive voluntary sampling method was used to select participants who met
the set criteria. Two populations were used, that is the patients co-infected with TB and
HIV, and the health workers who were involved in their care. In depth unstructured
interviews were conducted with the patient population and semi structured interviews with
the health worker population using an interview schedule that was formulated from the
background literature. Data was captured on an audiotape, and transcribed verbatim.
Field notes were taken immediately after each interview. The researcher and a co-coder
did data analysis after data saturation was reached and a consensus was reached on the
categories that emerged.
From the findings of this research it appeared that there were general perceptions by the
patients co-infected with TB and HIV that indicated stigmatisation by the health workers.
This perceived stigmatisation was reported as being perpetrated by all categories of health
workers. Negative behaviours such as the health workers not having time for the patients
and being impatient were reported. Lack of sufficient knowledge was related to these
behaviours especially amongst lower categories or non-professional health workers. In
spite of the above, the researcher also observed that there was a limited number of health
workers who were still being perceived as committed and caring by the patients co-infected
with TB and HIV.
The researcher concluded that the relationship between the health workers and the
patients co-infected with TB and HIV was characterised by conflict. The health workers
seemed to perceive the patients co-infected with TB and HIV as stubborn, harsh, abuse
alcohol, manipulative and not taking responsibility of their illness. These perceptions lead
the health workers to have a negative attitude towards these patients and occasionally
came across as unsympathetic towards them. On the other hand the researcher observed
that there were other health workers who did not present with negative behaviours towards
these patients and tried to understand the reasons for their sometimes-unacceptable
behaviours.
Recommendations are made for the field of nursing education, community health nursing
practice and nursing research with the formulation of guidelines for health workers so as to
facilitate the utilization of the health services by the patients co-infected with TB and HIV.
The guidelines are discussed under three main categories, namely guidelines for the
health workers to facilitate the utilization of the health services by the patients co-infected
with TB and HIV, guidelines to improve the utilization of the health services more efficiently
and adequately by the patients co-infected with TB and HIV, and guidelines to improve the
attitudes of the health workers towards the patients co-infected with TB and HIV with the
intention of improving the utilization of the health services by these patients. / Thesis (M.Cur.)--North-West University, Potchefstroom Campus, 2006.
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Stigmatisation of a patient co-infected with TB and HIV / Deliwe René PhetlhuPhetlhu, Deliwe René January 2005 (has links)
The last few years have seen an increase in the infection rate not only of HIV but also TB.
The HIV/AIDS pandemic is increasing rapidly mainly in developing countries with 71 % of
infections in the Sub-Saharan region of Africa. South Africa, which forms part of the Sub-
Saharan region, has the highest infection rate in the world with 3.2 to 3.4 million people
living with HIV/AIDS. People with HIV are especially vulnerable to TB, and HIV pandemic
is fuelling an explosive growth in TB cases. The increase in the infection rate of TB and
HIV exert increased pressure on health service delivery thus reflecting the serious problem
in the country with regard to health service delivery to people co-infected with TB and
HlV/AlDS.
Health service delivery is also hindered by negative attitudes of health workers that have
been reported towards people living with HIV/AIDS. They entertain a biased view of their
own risk, considering risk only from occupational exposure and denying the possibility of
infection in their private life. These attitudes of health workers decreases the quality of
care and support delivered to patient co-infected with TB and HIV. This result in people
not disclosing their illness even in cases were treatment is available like TB for the fear of
stigmatisation. Hence the problem of stigmatisation escalates into a dilemma for the
patient co-infected with TB and HIV. Therefore these patients tend to shy away from
health services and isolate themselves due to fear of being stigmatised twice.
The need to address TB and HIV together in the light of this dimension is urgent so as to
improve the utilization of the health services by people co-infected with Ti3 and HIV. The
purpose of this research was to explore and describe the experiences of patients co-infected
with TB and HIV regarding stigmatisation by the health workers, to explore and
describe the attitudes of health workers towards patients co-infected with TB and HIV, and
to formulate guidelines for health workers that will facilitate the health service utilization by
patients co-infected with TB and HIV in the Potchefstroom district.
The research was conducted in the Potchefstroom district in the North West province of
South Africa. A qualitative research design was used to explore and describe the
experiences of patients co-infected with TB and HIV regarding stigmatisation by the health
workers, and to explore and describe the attitudes of health workers toward co-infected
patients. A purposive voluntary sampling method was used to select participants who met
the set criteria. Two populations were used, that is the patients co-infected with TB and
HIV, and the health workers who were involved in their care. In depth unstructured
interviews were conducted with the patient population and semi structured interviews with
the health worker population using an interview schedule that was formulated from the
background literature. Data was captured on an audiotape, and transcribed verbatim.
Field notes were taken immediately after each interview. The researcher and a co-coder
did data analysis after data saturation was reached and a consensus was reached on the
categories that emerged.
From the findings of this research it appeared that there were general perceptions by the
patients co-infected with TB and HIV that indicated stigmatisation by the health workers.
This perceived stigmatisation was reported as being perpetrated by all categories of health
workers. Negative behaviours such as the health workers not having time for the patients
and being impatient were reported. Lack of sufficient knowledge was related to these
behaviours especially amongst lower categories or non-professional health workers. In
spite of the above, the researcher also observed that there was a limited number of health
workers who were still being perceived as committed and caring by the patients co-infected
with TB and HIV.
The researcher concluded that the relationship between the health workers and the
patients co-infected with TB and HIV was characterised by conflict. The health workers
seemed to perceive the patients co-infected with TB and HIV as stubborn, harsh, abuse
alcohol, manipulative and not taking responsibility of their illness. These perceptions lead
the health workers to have a negative attitude towards these patients and occasionally
came across as unsympathetic towards them. On the other hand the researcher observed
that there were other health workers who did not present with negative behaviours towards
these patients and tried to understand the reasons for their sometimes-unacceptable
behaviours.
Recommendations are made for the field of nursing education, community health nursing
practice and nursing research with the formulation of guidelines for health workers so as to
facilitate the utilization of the health services by the patients co-infected with TB and HIV.
The guidelines are discussed under three main categories, namely guidelines for the
health workers to facilitate the utilization of the health services by the patients co-infected
with TB and HIV, guidelines to improve the utilization of the health services more efficiently
and adequately by the patients co-infected with TB and HIV, and guidelines to improve the
attitudes of the health workers towards the patients co-infected with TB and HIV with the
intention of improving the utilization of the health services by these patients. / Thesis (M.Cur.)--North-West University, Potchefstroom Campus, 2006.
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Black farm workers' beliefs on HIV and AIDS / Dintletse Maria MagcaiMagcai, Dintletse Maria January 2008 (has links)
In this dissertation, the argument is the understanding of the beliefs of Black farm workers regarding HIV and Aids and how these beliefs that protect them from being infected, will lead to the formulation of suggestions for a belief-sensitive approach, which can be incorporated by health care professionals in HIV and Aids-prevention programmes for Black farm workers.
Several authors stress the fact that if any HIV and Aids programme is to be implemented successfully, the health care profession should strive to know more about the beliefs of the community, in this case Black farm workers, so that there can be sound human relations and effective programmes.
Based on the problem statement for this study the following research questions were asked:
1. What are the beliefs of black farm workers regarding HIV and Aids?
2. How do these beliefs protect them from being infected?
3. Based on the answers to the first two questions, what suggestions can be formulated regarding a belief-sensitive approach in HIV and Aids-prevention programmes for Black farm workers?
The objectives were in line with these questions, namely to explore and describe the beliefs of Black farm workers regarding HIV and Aids; to explore and describe how these beliefs protect them from being infected; and to formulate recommendations, specifically suggestions regarding a belief-sensitive approach in HIV and Aids-prevention programmes for Black farm workers.
The study followed a qualitative, explorative and descriptive approach. A participatory rural appraisal (PRA) approach was used to collect data. 'Lekgotla' was used as a strategy to collect data.
The results indicated that Black farm workers do have beliefs about HIV and Aids. Most of the beliefs they uphold protect them from being infected, however there are some marginal beliefs that can put them at risk of being infected.
Suggestions, which health care professionals can incorporate in HIV and Aids-prevention programmes for Black farm workers, were formulated based on the results, a literature control and ensuing conclusions. Beliefs of Black farm workers that protect them from being infected could be included in the suggestions for prevention strategies. Health care professionals involved in prevention strategies should actively listen to Black farm workers’ beliefs in order for these strategies to be successful. / Thesis (M.Cur.)--North-West University, Potchefstroom Campus, 2009.
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Black farm workers' beliefs on HIV and AIDS / Dintletse Maria MagcaiMagcai, Dintletse Maria January 2008 (has links)
In this dissertation, the argument is the understanding of the beliefs of Black farm workers regarding HIV and Aids and how these beliefs that protect them from being infected, will lead to the formulation of suggestions for a belief-sensitive approach, which can be incorporated by health care professionals in HIV and Aids-prevention programmes for Black farm workers.
Several authors stress the fact that if any HIV and Aids programme is to be implemented successfully, the health care profession should strive to know more about the beliefs of the community, in this case Black farm workers, so that there can be sound human relations and effective programmes.
Based on the problem statement for this study the following research questions were asked:
1. What are the beliefs of black farm workers regarding HIV and Aids?
2. How do these beliefs protect them from being infected?
3. Based on the answers to the first two questions, what suggestions can be formulated regarding a belief-sensitive approach in HIV and Aids-prevention programmes for Black farm workers?
The objectives were in line with these questions, namely to explore and describe the beliefs of Black farm workers regarding HIV and Aids; to explore and describe how these beliefs protect them from being infected; and to formulate recommendations, specifically suggestions regarding a belief-sensitive approach in HIV and Aids-prevention programmes for Black farm workers.
The study followed a qualitative, explorative and descriptive approach. A participatory rural appraisal (PRA) approach was used to collect data. 'Lekgotla' was used as a strategy to collect data.
The results indicated that Black farm workers do have beliefs about HIV and Aids. Most of the beliefs they uphold protect them from being infected, however there are some marginal beliefs that can put them at risk of being infected.
Suggestions, which health care professionals can incorporate in HIV and Aids-prevention programmes for Black farm workers, were formulated based on the results, a literature control and ensuing conclusions. Beliefs of Black farm workers that protect them from being infected could be included in the suggestions for prevention strategies. Health care professionals involved in prevention strategies should actively listen to Black farm workers’ beliefs in order for these strategies to be successful. / Thesis (M.Cur.)--North-West University, Potchefstroom Campus, 2009.
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Factors associated with non-adherence to antiretroviral (ARV) treatment in adults at a hospital in NamibiaChigova, Temptation 11 1900 (has links)
The questionnaire text in English, Afrikaans and Native language / The aim of the study was to minimise non-adherence to antiretroviral (ARV) treatment
amongst HIV/AIDS adult patients at a hospital in Namibia thereby promoting successful
outcomes in patients on ARV treatment. A quantitative cross-sectional descriptive study
was conducted on a sample of 112 non-adherent adults. Data collection was through
structured interviews and patients’ records review. Data analysis was by descriptive
statistics. Rate of non-adherence was 36.7%. Characteristics common in the sample
were, being a woman, age of 31-45 years, being unmarried, low educational status, lack
of HIV status disclosure, feeling that taking ARVs reminded one of HIV and experience
of ARV side effects. Reasons for missed doses included forgetting, alcohol use, access
to care, work commitments, lack of food, stress and travelling. Of the respondents, 86.6%
had unsupressed viral loads. Recommendations include use of reminders, automated
SMS, establishing treatment supporters and collaborative efforts in reducing active
substance use to improve adherence. / Health Studies / M.A. (Nursing Science)
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The development of a user-friendly support programme for adolescents living with perinatally acquired human immunodeficiency virus in the Vhembe District of Limpopo Province, South AfricaMabasa, Rirhandzu Austice January 2022 (has links)
Thesis (Ph.D. (Public Health)) -- University of Limpopo, 2022 / There has a significant rise in the number of HIV-infected adolescents who were missed as children and are diagnosed with perinatally acquired HIV as teenagers. In 2013, perinatally
acquired HIV was estimated at around 10 000 infections globally, a figure which ballooned to38 000 by 2017. Adolescents living with perinatal HIV experience emotional upheaval as a result of their positive HIV diagnosis, which is exacerbated by real or perceived negative effects
on their relationships, career, and family aspirations. They face the same challenges as other
adolescents, along with the added complexity of personal decisions relating to their sexual
conduct having a direct impact on the global cause to eradicate HIV/AIDS. An extensive body
of literature indicates a need for emotional and psychosocial support as existing management
focuses mainly on the physical aspects of infection and treatment.
Aim of the study
The aim of the study was to explore the challenges faced by adolescents living with perinatal
HIV infection and to evaluate the designed user-friendly support programme in response to
formative findings of the research in selected clinics and community health centres in the
Vhembe District of the Limpopo Province in South Africa.
Methodology
A mixed-methods sequential exploratory design was employed to fulfil the purpose of the study.
Data was collected in two phases. In qualitative phase- a total of 21 participants were
interviewed using a semi-structured interview guide. The sample was purposefully selected from
adolescents living with HIV/AIDS. In quantitative phase a total of 213 people participated in data
collection using a questionnaire. Thematic approach was used to analyse qualitative data using
Tesch’s eight steps of qualitative data analysis. Quantitative data was analysed using SPSS
version 25. Descriptive statistics was used to explain and summarize data. Fischer’s test was
done to establish significance of association between alcohol used, condom use and between
age and gender.
The results
The results revealed that adolescents with perinatally acquired HIV face more challenges. They
had psychosocial, emotional and economic challenges more than their peers. The current
HIV/AIDS management and care has not yet recognised the specific needs these adolescents
have related to their care. They have been incorporated into the general adulthood HIV/AIDS
making their transition from childhood adolescence difficult. Suggestions for a mentor, and ARV
modification were made and a need for a support programme emerged as one of the major
themes
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The perception of preparatory students of the risk of contracting human immuno-deficiency virus and sexually transmitted infections in Adama, Eastern Showa, Oromia Regional State, EthiopiaRegebe Berhanu Belay 03 October 2014 (has links)
This study explored preparatory students’ perceptions of the risk of contracting the
Human Immuno-deficiency Virus (HIV) and sexually transmitted infections (STIs) in
Ethopia. It utilised a non-experimental exploratory survey methodology. A range of
findings was revealed. Most respondents (67.14%) were knowledgeable about
HIV/AIDS and more than half of the respondents knew about STIs. A significant number
of respondents (67.1%) were able to describe HIV transmission prevention methods.
Twenty one percent of respondents were sexually active and 17.0% of these reported to
have used condoms. Twenty nine percent and 4.25% of the respondents had selfperceived
risk of contracting HIV infection and STIs respectively. In spite of increased
awareness of HIV/AIDS, school youths still engage in high-risk sexual activities and
believe that they are unlikely to contract the disease. The study findings have
implications for practice, and recommendations are offered for further research / Health Studies / M.A. (Public Health)
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Targeting The CD4 Biniding Site In HIV-1 Immunogen DesignBhattacharyya, Sanchari 07 1900 (has links) (PDF)
Over three decades have passed since the discovery of HIV-1, yet an AIDS vaccine remains elusive. The envelope glycoprotein of HIV-1 gp120, is the most exposed protein on the viral surface and thus serves as an important target for vaccine design. However, various factors like high mutability of gp120, extensive glycosylation and very high conformational flexibility of gp120 have confounded all efforts to design a suitable immunogen that elicits broad and potent neutralizing antibodies against HIV-1. In Chapter 1, a brief description of the structural organization of HIV-1 along with the progress made and the difficulties encountered in the development of a vaccine are presented.
In Chapter 2, the design and characterization of an outer domain immunogen of HIV-1 gp120 is discussed. The outer domain (OD) of the envelope glycoprotein gp120 is an important target for vaccine design since it contains a number of conserved epitopes, including a large fraction of the CD4 binding site. Attempts to design OD based immunogens in the past have met with little success. In this work, we designed an OD immunogen based on the sequence of the HXBc2 strain, expressed and purified it from E. coli (ODEC). The ODEC molecule lacks the variable loops V1V2 and V3 and incorporates 11 designed mutations at the interface of the inner and the outer domains of gp120 to increase solubility. Biophysical studies showed that ODEC is folded and protease resistant while ODEC lacking the designed mutations is highly aggregation prone. In contrast to previously characterized OD constructs, ODEC bound CD4 and the broadly neutralizing antibody b12 with micromolar affinities, but not the non-neutralizing antibodies b6 and F105. Further improvement in the refolding protocol yielded a better structured molecule that bound CD4, b12 and VRC01 with sub-micromolar affinities. In rabbit immunization studies with animals primed with ODEC and boosted with gp120, the sera are able to neutralize Tier I viruses and some Tier II viruses like JRFL and RHPA with measurable IC50s. This is one of the first examples of a gp120 fragment based immunogen which was able to elicit sera that showed modest neutralization of some Tier II viruses. Subsequently amide hydrogen-deuterium exchange studies of ODEC showed that though the molecule is well-folded, it is labile to exchange. This might indicate why ODEC does not elicit high amounts of neutralizing antibodies.
In Chapter 3, we report the design and characterization of two smaller fragments of gp120 (b121a and b122a) to target the epitope of the broadly neutralizing antibody b12. The region chosen comprised of a compact beta barrel in the lower part of the outer domain of gp120. Unlike ODEC, the fragments corresponding to these constructs were not contiguous stretches in gp120. Thus we used linkers to connect them. Further, nine designed mutations were introduced at exposed hydrophobic regions of the fragment to increase its solubility. The designed protein fragments were expressed in E. coli in order to prevent glycosylation and consequent epitope masking that might occur if expressed in an eukaryotic expression system. Biophysical studies showed that b121a/b122a are partially folded. Disulfide mapping studies showed that the expected disulfide bridges were formed. The designed immunogens could bind b12, but not the non-neutralizing antibody b6. Sera from rabbits primed with b121a/b122a protein fragments and boosted with full-length gp120 showed broad neutralizing activity against a 20 virus panel including Tier2 and 3 viruses such as PVO4, CAAN, CAP45 and ZM233. Sera from animals that received only gp120 showed substantially decreased breadth and potency. Serum depletion studies confirmed that neutralization was gp120 directed and that a substantial fraction of it was mediated by CD4 binding site (CD4bs) antibodies. The data demonstrate that it is possible to elicit broadly neutralizing sera against HIV-1 in small animals, despite the restricted germline VH gene usage observed so far in broadly neutralizing CD4bs directed antibodies in humans.
In Chapter 3, we also discuss design of a new construct b122d, which includes regions corresponding to b121a, but with linker connectivities similar to b122a. It was found to bind b12 with sub-micromolar affinity and also showed proteolytic resistance comparable to b121a. This indicated that though b121a showed better proteolytic resistance than b122a, it bound b12 poorly because one of the linkers might sterically occlude the b12 binding site.
As the b12 binding site constructs based on the subtype B HXBc2 sequence elicited neutralizing antibodies, we chose to design similar constructs based on a subtype C sequence. The proteins (Cb122a and Cb122d) were purified from E. coli, characterized and found to bind b12 with micromolar affinity. The new constructs (b122d, Cb122a, Cb122d) will shortly be tested in animal immunizations.
Disulfides are known to stabilize proteins by reducing the entropy of the unfolded state. In Chapter 4, we attempted to stabilize b122a by engineering disulfides. The disulfides are expected to rigidify the molecule and possibly improve its ability to elicit neutralizing antibodies. Some of the disulfides tested in b122a were predicted based on stereo-chemical criteria by the program MODIP (Modeling Disulfide Bridges in Proteins), while others were chosen at non-hydrogen bonded positions (NHB) on anti-parallel beta strands, based on earlier studies in the lab. Some of the disulfide mutants showed better binding to b12 and increased protection to enzymatic digestion. These disulfides were subsequently engineered into other b12 binding site constructs, namely b122d, Cb122a and Cb122d and these were biophysically characterized. Amongst the various disulfides that were tested in b122a, the one at 293-448 (according to HxBc2 numbering) was found to improve the binding to b12 by about ~16-fold. Not only did this disulfide improve the binding of b122a to b12, it also showed similar improvement in case of b122d and both the subtype C constructs tested. Moreover, since the position 293-448 is an exposed NHB position of an anti-parallel beta strand, spontaneous formation of the disulfide and the improved binding to b12 for all the proteins tested reinforces the fact that cysteines engineered at such positions leads to formation of a stabilizing disulfide. All the proteins containing the 293-448 disulfide will be used in future for rabbit immunization studies to examine if they elicit better neutralizing antibodies than the parent b122a molecule.
As discussed in Chapter 2, ODEC showed a very fast rate of hydrogen exchange, indicating that it is flexible. As the 293-448 disulfide improved the binding of b12 binding site constructs, in Chapter 5, disulfides at exposed NHB positions were introduced in the context of ODEC. Previously engineered inter-domain disulfides have been shown to reduce the conformational flexibility of gp120. The disulfides in the lower beta barrel of the outer domain which harbors the CD4 binding site were found to be monomeric, oxidized and could bind neutralizing CD4bs antibodies better than the WT protein. On the other hand, the disulfides in the upper barrel of the outer domain were aggregated and bound antibodies poorly compared to the WT protein, indicating that this part of the molecule may not be well structured in the fragment. However, there was no significant change in the hydrogen exchange kinetics for these mutants. Mutations in the Phe-43 cavity of gp120 (S375W/T257S) which constrain gp120 in the CD4 bound conformation were also tested in ODEC (ODEC-CF). This protein was found to bind CD4 and VRC01 about 8 and 2 times better respectively than WT ODEC. These improved immunogens will be used shortly in rabbit immunization studies.
In an attempt to improve the immunogenicity of the gp120 fragment proteins, b121a, b122a and ODEC were displayed on/conjugated to the surface of Qβ virus like particles in Chapter 6. Exposed single cysteine mutants of these proteins were purified, characterized biophysically and found to have the single cysteine free for conjugation. These were subsequently conjugated to the Qβ virus like particles through click chemistry (carried out in Prof. MG Finn’s lab at TSRI), purified and used for rabbit immunization studies. The gp120 ELISA titers of the elicited sera showed that conjugation may be a better option to display foreign antigens on the surface than genetic fusion. There was no difference in the ELISA titers with and without adjuvant, indicating that the particles are sufficiently immunogenic in themselves. Sera from these studies will be tested in neutralization assays. The overall utility of the particle based display approach will be assessed by comparing neutralization data from particle based immunizations to identical immunizations with unconjugated immunogens.
Most HIV-1 broadly neutralizing antibodies are directed against the gp120 subunit of the Env surface protein. Native Env consists of a trimer of gp120:gp41 heterodimers, and in contrast to monomeric gp120, preferentially binds CD4 binding site (CD4bs) directed neutralizing antibodies over non-neutralizing ones. Some cryo-electron tomography studies have suggested that the V1V2 loop regions of gp120 are located close to the trimer interface. To understand this further, in Chapter 7, we have designed cyclically permuted variants of gp120 with and without the h-CMP and SUMO2a trimerization domains inserted into the V1/V2 loop. h-CMP-V1cyc is one such variant where 153 and 142 are the N and C terminal residues of cyclically permuted gp120 and h-CMP is fused to the N-terminus. This molecule forms a trimer under native conditions and binds CD4 and the neutralizing CD4bs antibodies b12 with significantly higher affinity relative to wtgp120. It binds the non-neutralizing CD4bs antibody F105 with lower affinity than gp120. A similar derivative, h-CMP-V1cyc1 bound the V1V2 directed broadly neutralizing antibodies PG9/PG16 with ~20 fold higher affinity compared to wild type JRCSF gp120. These cyclic permutants of gp120 are properly folded and are potential immunogens. The data also support Env models in which the V1V2 loops are proximal to the trimer interface.
In Appendix A1, peptide analogs of selected secondary structural elements of gp120 were designed. Some of them were grafted on known scaffold proteins. The synthesized peptides were characterized biophysically. Most of the peptides did not have a well-defined secondary structure, indicating that they are not stable in isolation. Hence they were not pursued for further studies. One helical peptide adopted a significant amount of structure in aqueous buffer and will be shortly conjugated to carrier proteins and used in immunization studies.
In Appendix A2, we created error-prone PCR libraries and loop-randomization libraries of b12 binding site constructs and attempted to screen these for better b12 binding using phage-display. However the screening was unsuccessful as the phages showed non-specific binding to b12 antibody. These libraries will be screened in future using yeast display.
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The perception of preparatory students of the risk of contracting human immuno-deficiency virus and sexually transmitted infections in Adama, Eastern Showa, Oromia Regional State, EthiopiaRegebe Berhanu Belay 03 October 2014 (has links)
This study explored preparatory students’ perceptions of the risk of contracting the
Human Immuno-deficiency Virus (HIV) and sexually transmitted infections (STIs) in
Ethopia. It utilised a non-experimental exploratory survey methodology. A range of
findings was revealed. Most respondents (67.14%) were knowledgeable about
HIV/AIDS and more than half of the respondents knew about STIs. A significant number
of respondents (67.1%) were able to describe HIV transmission prevention methods.
Twenty one percent of respondents were sexually active and 17.0% of these reported to
have used condoms. Twenty nine percent and 4.25% of the respondents had selfperceived
risk of contracting HIV infection and STIs respectively. In spite of increased
awareness of HIV/AIDS, school youths still engage in high-risk sexual activities and
believe that they are unlikely to contract the disease. The study findings have
implications for practice, and recommendations are offered for further research / Health Studies / M.A. (Public Health)
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