Expanding ART for treatment and prevention of HIV in South Africa: estimated cost and cost-effectiveness 2011-2050

Background

Antiretroviral Treatment (ART) significantly reduces HIV transmission. We conducted a cost-effectiveness analysis of the impact of expanded ART in South Africa.

Methods

We model a best case scenario of 90% annual HIV testing coverage in adults 15–49 years old and four ART eligibility scenarios: CD4 count <200 cells/mm³ (current practice), CD4 count <350, CD4 count <500, all CD4 levels. 2011–2050 outcomes include deaths, disability adjusted life years (DALYs), HIV infections, cost, and cost per DALY averted. Service and ART costs reflect South African data and international generic prices. ART reduces transmission by 92%. We conducted sensitivity analyses.

Results

Expanding ART to CD4 count <350 cells/mm³ prevents an estimated 265,000 (17%) and 1.3 million (15%) new HIV infections over 5 and 40 years, respectively. Cumulative deaths decline 15%, from 12.5 to 10.6 million; DALYs by 14% from 109 to 93 million over 40 years. Costs drop $504 million over 5 years and $3.9 billion over 40 years with breakeven by 2013. Compared with the current scenario, expanding to <500 prevents an additional 585,000 and 3 million new HIV infections over 5 and 40 years, respectively. Expanding to all CD4 levels decreases HIV infections by 3.3 million (45%) and costs by $10 billion over 40 years, with breakeven by 2023. By 2050, using higher ART and monitoring costs, all CD4 levels saves $0.6 billion versus current; other ART scenarios cost $9–194 per DALY averted. If ART reduces transmission by 99%, savings from all CD4 levels reach $17.5 billion. Sensitivity analyses suggest that poor retention and predominant acute phase transmission reduce DALYs averted by 26% and savings by 7%.

Conclusion

Increasing the provision of ART to <350 cells/mm3 may significantly reduce costs while reducing the HIV burden. Feasibility including HIV testing and ART uptake, retention, and adherence should be evaluated.     

Analysis of a clonal lineage of HIV-1 envelope V2/V3 conformational epitope-specific broadly neutralizing antibodies and their inferred unmutated common ancestors

V2/V3 conformational epitope antibodies that broadly neutralize HIV-1 (PG9 and PG16) have been recently described. Since an elicitation of previously known broadly neutralizing antibodies has proven elusive, the induction of antibodies with such specificity is an important goal for HIV-1 vaccine development. A critical question is which immunogens and vaccine formulations might be used to trigger and drive the development of memory B cell precursors with V2/V3 conformational epitope specificity. In this paper we identified a clonal lineage of four V2/V3 conformational epitope broadly neutralizing antibodies (CH01 to CH04) from an African HIV-1-infected broad neutralizer and inferred their common reverted unmutated ancestor (RUA) antibodies. While conformational epitope antibodies rarely bind recombinant Env monomers, a screen of 32 recombinant envelopes for binding to the CH01 to CH04 antibodies showed monoclonal antibody (MAb) binding to the E.A244 gp120 Env and to chronic Env AE.CM243; MAbs CH01 and CH02 also bound to transmitted/founder Env B.9021. CH01 to CH04 neutralized 38% to 49% of a panel of 91 HIV-1 tier 2 pseudoviruses, while the RUAs neutralized only 16% of HIV-1 isolates. Although the reverted unmutated ancestors showed restricted neutralizing activity, they retained the ability to bind to the E.A244 gp120 HIV-1 envelope with an affinity predicted to trigger B cell development. Thus, E.A244, B.9021, and AE.CM243 Envs are three potential immunogen candidates for studies aimed at defining strategies to induce V2/V3 conformational epitope-specific antibodies.     

Applications of β-gal-III isozyme from Bacillus coagulans RCS3, in lactose hydrolysis

Bacillus coagulans RCS3 isolated from hot water springs secreted five isozymes i.e. β-gal I-V of β-galactosidase. β-gal III isozyme was purified using DEAE cellulose and Sephadex G 100 column chromatography. Its molecular weight characterization showed a single band at 315 kD in Native PAGE, while two subunits of 50.1 and 53.7 kD in SDS PAGE. β-Gal III had pH optima in the range of 6-7 and temperature optima at 65 °C. It preferred nitro-aryl-β-d-galactoside as substrate having K_m of 4.16 mM with ONPG. More than 85% and 80% hydrolysis of lactose (1-5%, w/v) was recorded within 48 h of incubation at 55 °C and 50 °C respectively and pH range of 6-7. About 78-86% hydrolysis of lactose in various brands of standardized milk was recorded at incubation temperature of 50 °C. These results marked the applications of β-gal III in processing of milk/whey industry.     

Rapid Implementation of an Integrated Large-Scale HIV Counseling and Testing,Malaria, and Diarrhea Prevention Campaign in Rural Kenya

Background

Integrated disease prevention in low resource settings can increase coverage, equity and efficiency in controlling high burden infectious diseases. A public-private partnership with the Ministry of Health, CDC, Vestergaard Frandsen and CHF International implemented a one-week integrated multi-disease prevention campaign.

Method

Residents of Lurambi, Western Kenya were eligible for participation. The aim was to offer services to at least 80% of those aged 15–49. 31 temporary sites in strategically dispersed locations offered: HIV counseling and testing, 60 male condoms, an insecticide-treated bednet, a household water filter for women or an individual filter for men, and for those testing positive, a 3-month supply of cotrimoxazole and referral for follow-up care and treatment.

Findings

Over 7 days, 47,311 people attended the campaign with a 96% uptake of the multi-disease preventive package. Of these, 99.7% were tested for HIV (87% in the target 15–49 age group); 80% had previously never tested. 4% of those tested were positive, 61% were women (5% of women and 3% of men), 6% had median CD4 counts of 541 cell/µL (IQR; 356, 754). 386 certified counselors attended to an average 17 participants per day, consistent with recommended national figures for mass campaigns. Among women, HIV infection varied by age, and was more likely with an ended marriage (e.g. widowed vs. never married, OR.3.91; 95% CI. 2.87–5.34), and lack of occupation. In men, quantitatively stronger relationships were found (e.g. widowed vs. never married, OR.7.0; 95% CI. 3.5–13.9). Always using condoms with a non-steady partner was more common among HIV-infected women participants who knew their status compared to those who did not (OR.5.4 95% CI. 2.3–12.8).

Conclusion

Through integrated campaigns it is feasible to efficiently cover large proportions of eligible adults in rural underserved communities with multiple disease preventive services simultaneously achieving various national and international health development goals.     

Classifications of ovarian cancer tissues by proteomic patterns

Ovarian cancer is a morphologically and biologically heterogeneous disease. The identification of type-specific protein markers for ovarian cancer would provide the basis for more tailored treatments, as well as clues for understanding the molecular mechanisms governing cancer progression. In the present study, we used a novel approach to classify 24 ovarian cancer tissue samples based on the proteomic pattern of each sample. The method involved fractionation according to pI using chromatofocusing with analytical columns in the first dimension followed by separation of the proteins in each pI fraction using nonporous RP HPLC, which was coupled to an ESI-TOF mass analyzer for molecular weight (MW) analysis. A 2-D mass map of the protein content of each type of ovarian cancer tissue samples based upon pI versus intact protein MW was generated. Using this method, the clear cell and serous ovarian carcinoma samples were histologically distinguished by principal component analysis and clustering analysis based on their protein expression profiles and subtype-specific biomarker candidates of ovarian cancers were identified, which could be further investigated for future clinical study.     

Elucidation of underlying molecular mechanism of 5-Fluorouracil chemoresistance and its restoration using fish oil in experimental colon carcinoma

Molecular and Cellular Biochemistry - Latest strategies for cancer treatment primarily focus on the use of chemosensitizers to enhance therapeutic outcome. N-3 PUFAs have emerged as the strongest...     

Adsorption of Mycobacterium avium subsp. paratuberculosis to Soil Particles

Attachment of Mycobacterium avium subsp. paratuberculosis to soil particles could increase their availability to farm animals, as well as influence the transportation of M. avium subsp. paratuberculosis to water sources. To investigate the possibility of such attachment, we passed a known quantity of M. avium subsp. paratuberculosis through chromatography columns packed with clay soil, sandy soil, pure silica, clay-silica mixture, or clay-silica complexes and measured the organisms recovered in the eluent using culture or quantitative PCR. Experiments were repeated using buffer at a range of pH levels with pure silica to investigate the effect of pH on M. avium subsp. paratuberculosis attachment. Linear mixed-model analyses were conducted to compare the proportional recovery of M. avium subsp. paratuberculosis in the eluent between different substrates and pH levels. Of the organisms added to the columns, 83 to 100% were estimated to be retained in the columns after adjustment for those retained in empty control columns. The proportions recovered were significantly different across different substrates, with the retention being significantly greater (P < 0.05) in pure substrates (silica and clay-silica complexes) than in soil substrates (clay soil and sandy soil). However, there were no significant differences in the retention of M. avium subsp. paratuberculosis between silica and clay-silica complexes or between clay soil and sandy soil. The proportion retained decreased with increasing pH in one of the experiments, indicating greater adsorption of M. avium subsp. paratuberculosis to soil particles at an acidic pH (P < 0.05). The results suggest that under experimental conditions M. avium subsp. paratuberculosis adsorbs to a range of soil particles, and this attachment is influenced by soil pH.Mycobacterium avium subsp. paratuberculosis is a pathogen of great significance for livestock since it causes a fatal and economically important disease called paratuberculosis or Johne''s disease (JD). The significance of M. avium subsp. paratuberculosis has further increased due to speculation over its role in the causation of Crohn''s disease in humans (10). Although reports trying to establish a causative association between M. avium subsp. paratuberculosis and Crohn''s disease are conflicting and inconclusive, they have aroused concerns among public health authorities (13); therefore, greater attention is now being paid to understand the natural ecology of M. avium subsp. paratuberculosis (32, 34). We investigated a largely unexplored aspect of the natural ecology of M. avium subsp. paratuberculosis: its attachment to soil particles, which could influence its availability to farm animals and humans (see below).Bacteria can become loosely associated with clay or soil particles through reversible adsorption mediated by electrostatic and van der Waals'' forces or by cell surface hydrophobicity (20). An irreversible firm attachment may later occur usually mediated by extracellular bridging polymers (8). The attachment of microbiota such as Escherichia coli, Arthrobacter spp., and poliovirus to soil or clay particles has been reported previously (2, 3, 11, 22, 26), but there is only indirect evidence of the association of mycobacteria with soil particles. A study reported the recovery of only 3.5% of nontuberculous mycobacteria inoculated into soil samples and attributed this to their adsorption to clay particles (5). Later, a similar phenomenon was inferred for M. avium subsp. paratuberculosis because 99% of these organisms in feces could not be detected upon culture of feces mixed with soil, suggesting the binding of M. avium subsp. paratuberculosis to soil particles (33). An association between M. avium subsp. paratuberculosis and clay particles was also suggested by an epidemiological study conducted to investigate the risk factors for ovine JD, indicating the possibility of bacterial attachment to clay particles (6).M. avium subsp. paratuberculosis is transmitted primarily by the feco-oral route. Infected animals shed huge numbers of M. avium subsp. paratuberculosis in their feces (29, 35), thus contaminating soil and the farm environment. The ability of M. avium subsp. paratuberculosis to survive for extended periods in an external environment, in spite of it being an obligate parasite (32, 34), facilitates the build-up of soil and pasture contamination levels over time. The attachment of M. avium subsp. paratuberculosis to soil particles could help retain the bacteria in the upper layers of the soil, thus further enhancing contamination levels. The contaminated farm environment thus becomes a potential source of infection for farm animals because grazing ruminants normally consume soil with pasture, and the amounts can be substantial, up to 300 or more grams per day for sheep (9, 21).In addition, runoff from contaminated farm soils can contaminate water bodies (23), which can be a potential health hazard for humans because the routine chlorine disinfection of water is not able to eliminate M. avium subsp. paratuberculosis completely (28). The transportation of bacteria from the farm environment to water sources is influenced by their attachment to soil or clay particles (11, 12). Generally, bacterial adsorption to soil particles decreases the rate of transportation through soil (3), but it also helps retain bacteria in the top surface layers of the soil, thus increasing the possibility of the contamination of runoff water (24). Note that soil particles can be dislodged and moved by wind, water, and mechanical factors.The aim of the present study was to verify whether M. avium subsp. paratuberculosis attaches to clay and other soil particles and whether this attachment is influenced by soil pH. The study findings improve our knowledge and understanding of the natural ecology of M. avium subsp. paratuberculosis.     

Sodium-independent low-affinity D-glucose transport by human sodium/D-glucose cotransporter 1: critical role of tryptophan 561

Although there is no evidence of significant Na-independent glucose flux in tissues naturally expressing SGLT1, previous kinetic and biophysical studies suggest that sodium/d-glucose cotransporter 1 (hSGLT1) can facilitate sodium-independent d-glucose transport and may contain more than one sugar binding site. In this work, we analyze the kinetic properties and conformational states of isolated hSGLT1 reconstituted in liposomes by transport and fluorescence studies in the absence of sodium. In the transport studies with hSGLT1, significant sodium-independent phlorizin inhibitable alpha-methyl d-glucopyranoside (alpha-MDG) uptake was observed which amounted to approximately 20% of the uptake observed in the presence of a sodium gradient. The apparent affinity constant for alpha-MDG was thereby 3.4 +/- 0.5 mM, a value approximately 10-fold higher than that in the presence of sodium. In the absence of sodium, various sugars significantly decreased the intrinsic Trp fluorescence of hSGLT1 in proteoliposomes exhibiting the following sequence of affinities: alpha-MDG > d-glucose approximately d-galactose > 6-deoxy-d-glucose > 2-deoxy-d-glucose > d-allose. Furthermore, significant protection effects of d-glucose or phlorizin against potassium iodide, acrylamide, or trichloroethanol quenching were observed. To locate the Trps involved in this reaction, we generated mutants in which all Trps were sequentially substituted with Phe. None of the replacements significantly affected sodium-dependent uptake. Uptake in the absence of sodium and typical fluorescence changes depended, however, on the presence of Trp at position 561. This Trp residue is conserved in all known SGLT1 forms (except Vibrio parahaemolyticus SGLT) and all SGLT isoforms in humans (except hSGLT3). If all these data are taken into consideration, it seems that Trp-561 in hSGLT1 forms part of a low-affinity sodium-independent binding and/or translocation site for d-glucose. The rate of sodium-independent translocation via hSGLT1 seems, however, to be tightly regulated in the intact cell by yet unknown factors.     

Purification and characterization of a trypsin inhibitor from Putranjiva roxburghii seeds

A highly stable and potent trypsin inhibitor was purified to homogeneity from the seeds of Putranjiva roxburghii belonging to Euphorbiaceae family by acid precipitation, cation-exchange and anion-exchange chromatography. SDS-PAGE analysis, under reducing condition, showed that protein consists of a single polypeptide chain with molecular mass of approximately 34 kDa. The purified inhibitor inhibited bovine trypsin in 1:1 molar ratio. Kinetic studies showed that the protein is a competitive inhibitor with an equilibrium dissociation constant of 1.4x10(-11) M. The inhibitor retained the inhibitory activity over a broad range of pH (pH 2-12), temperature (20-80 degrees C) and in DTT (up to100 mM). The complete loss of inhibitory activity was observed above 90 degrees C. CD studies, at increasing temperatures, demonstrated the structural stability of inhibitor at high temperatures. The polypeptide backbone folding was retained up to 80 degrees C. The CD spectra of inhibitor at room temperature exhibited an alpha, beta pattern. N-terminal amino acid sequence of 10 residues did not show any similarities to known serine proteinase inhibitors, however, two peptides obtained by internal partial sequencing showed significant resemblance to Kunitz-type inhibitors.