Stability in care and risk of loss to follow-up among clients receiving community health worker-led differentiated HIV care: Results from a prospective cohort study in northern Tanzania.

BACKGROUND: HIV services in Tanzania are facility-based but facilities are often overcrowded. Differentiated care models (DCM) have been introduced into the National Guidelines. We piloted a Community Health Worker (CHW)-led HIV treatment club model (CHW-DCM) in an urban region, and assessed its effectiveness in comparison to the standard of care (SoC, facility-based model), in terms of stability in care, loss to follow-up (LTFU) and treatment adherence. METHODS: In two clinics in the Shinyanga region, clients established on ART (defined as stable clients by national guidelines as on first-line ART >6 months, undetectable viral load, no opportunistic infections or pregnancy, and good adherence) were offered CHW-DCM. This prospective cohort study included all stable clients who enrolled in CHW-DCM between July 2018 and March 2020 (CHW-DCM) and compared them to stable clients who remained in SoC during that period. Multivariable Cox regression models were used to analyse factors associated with continued stability in care and the risk of LTFU during 18 months of follow-up; treatment adherence was assessed by pill count and compared using Chi-square tests. RESULTS: Of 2472 stable clients, 24.5% received CHW-DCM and 75.5% SoC. CHW-DCM clients were slightly older (mean 42.8 vs. 37.9 years) and more likely to be female (36.2% vs. 32.2%). Treatment adherence was better among CHW-DCM than SoC: 96.6% versus 91.9% and 98.5% versus 92.2%, respectively (both p = 0.001). SoC clients were more likely to not remain stable over time than CHW-DCM (adjusted Hazard ratio [AHR] = 2.68; 95% CI: 1.86-3.90). There was no difference in LTFU (adjusted hazard ratio [AHR] = 1.54; 95%CI: 0.82-2.93). CONCLUSION: Clients attending CHW-DCM demonstrated better stability in care and treatment adherence than SoC, and the risk of LTFU was not increased. These findings demonstrate the potential of CHW in delivering community-based HIV services in the local Tanzanian context. These results could be used to extend this CHW-DCM model to similar settings.

Fast Solution-Phase and Liquid-Phase Peptide Syntheses (SolPSS and LPPS) Mediated by Biomimetic Cyclic Propylphosphonic Anhydride (T3P®).

The growing applications of peptide-based therapeutics require the development of efficient protocols from the perspective of an industrial scale-up. T3P® (cyclic propylphosphonic anhydride) promotes amidation in the solution-phase through a biomimetic approach, similar to the activation of carboxylic moiety catalyzed by ATP-grasp enzymes in metabolic pathways. The T3P® induced coupling reaction was applied in this study to the solution-phase peptide synthesis (SolPPS). Peptide bond formation occurred in a few minutes with high efficiency and no epimerization, generating water-soluble by-products, both using N-Boc or N-Fmoc amino acids. The optimized protocol, which was successfully applied to the iterative synthesis of a pentapeptide, also allowed for a decrease in the solvent volume, thus improving process sustainability. The protocol was finally extended to the liquid-phase peptide synthesis (LPPS), where the isolation of the peptide was performed using precipitation, thus also showing the suitability of this coupling reagent to this emerging technique.

Molecular Ruthenium Cyclopentadienone Bifunctional Catalysts for the Conversion of Sugar Platforms to Hydrogen.

Molecular ruthenium cyclopentadienone complexes were employed for the first time as pre-catalysts in the homogeneously catalysed Aqueous Phase Reforming (APR) of glucose. Shvo's complex resulted the best pre-catalyst (loading 2 mol %) with H2 yields up to 28.9 % at 150 °C. Studies of the final mixture allowed to identify the catalyst's resting state as a mononuclear dicarbonyl complex in the extracted organic fraction. In situ NMR experiments and HPLC analyses on the aqueous fraction gave awareness of the presence of sorbitol, fructose, 5-hydroxymethylfurfural and furfural as final fate or intermediates in the transformations under APR conditions. These results were summarized in a proposed mechanism, with particular emphasis on the steps where hydrogen was obtained as the product. Benzoquinone positively affected the catalyst activation when employed as an equimolar additive.

Effectiveness of provider-initiated versus client-initiated HIV testing by different health facility departments in Northern Tanzania.

BACKGROUND: HIV prevalence in Tanzania is still high at 4.7% among adults. Regular HIV testing is consistently advocated in the country to increase the level of awareness of HIV status, thus contributing to national HIV prevention. We report findings from three years of implementation of an HIV Test and Treat project utilizing provider-initiated and client-initiated testing and counselling (PITC and CITC). This study compared the effectiveness of PITC versus CITC in HIV case detection by the different departments of health facilities. METHOD: This retrospective cross-sectional study used health facility-based HIV testing data collected from adults aged 18 years and above between June 2017 - July 2019 in the Shinyanga region, Tanzania. Chi-square and logistic regression analysis were used to assess determinants of yield (HIV positivity). RESULTS: A total of 24,802 HIV tests were performed of which 15,814 (63.8%) were by PITC and 8,987 (36.2%) by CITC. Overall HIV positivity was 5.7%, higher among CITC at 6.6% than PITC at 5.2%. TB and IPD departments had the highest HIV positivity 11.8% and 7.8% respectively. Factors associated with a positive test were testing at a department in the facility compared to CITC, first-time test, and being or having been married compared to being single. CONCLUSION: Success in identifying HIV + patients was highest among people visiting the clinic for HIV testing (CITC) and first-time testers. With PITC, HIV + patient detection differed between departments, suggesting divergent risk profiles of respective clients and/or divergent HIV alertness of staff. This underscores the importance of increased targeting for PITC to identify HIV + patients.

Fast MacMillan's Imidazolidinone-Catalyzed Enantioselective Synthesis of Polyfunctionalized 4-Isoxazoline Scaffolds.

The enantioselective 1,3-dipolar cycloaddition of nitrones and arylpropionaldehydes to generate highly functionalized scaffolds for application in drug discovery was herein investigated. The use of a second-generation MacMillan catalyst as hydrochloride salt consistently accelerated the reaction speed, allowing a decrease in the reaction time up to >100 times, still affording 4-isoxazolines with good to excellent enantiomeric ratios at room temperature. As a proof of concept, further functionalization of the isoxazoline core through Pd-catalyzed cross-coupling was performed, generating differently functionalized chemical architectures in high yield.

Community- and facility-based HIV testing interventions in northern Tanzania: Midterm results of Test & Treat Project.

Test & Treat Project offers universal HIV testing and access to antiretroviral treatment in Northern Tanzania. The current cross-sectional study provides midterm results on HIV testing and counseling activities through community outreaches and facility-based services. A total 255,329 HIV tests were performed: 198,451 (77.7%) during testing campaigns in the villages, 12,592 (4.9%) during special events outreach and 44,286 (17.4%) in the health facilities. Females represented 53.8% (23,809) among those tested in the health facilities, while males were the majority in the community (54.4%, 114,835). Over one third of tests (n = 104,605, 41%) were performed among first-time testers. The overall HIV positivity rate was 1.2%, ranging from 0.7% in the community to 3.8% in the health facilities and decreased over time. Using a multivariable analysis, a positive test result was associated with age ≥ 50 years (PR 1.22, 95% CI 1.11 to 1.34), with female gender (PR 1.61, 95% CI 1.50 to 1.73), being tested in health facilities (PR 5.00, 95% CI 4.65 to 5.36) and for the first time (PR 1.86, 95% CI 1.73 to 2.00). The estimated proportion of PLHIV who knew their status of the project area increased by 28.6% (from 35.7% to 64.3%) and 11.1% (from 57.7% to 68.8%) in the project areas of Shinyanga and Simiyu regions respectively. Reaching the first UNAIDS 90 target by the end of this project seems possible. Future strategies should focus on improving PITC coverage, implementing more targeted testing modalities, together with current universal community-based approach.

Quality of care in a differentiated HIV service delivery intervention in Tanzania: A mixed-methods study.

BACKGROUND: Differentiated service delivery (DSD) offers benefits to people living with HIV (improved access, peer support), and the health system (clinic decongestion, efficient service delivery). ART clubs, 15-30 clients who usually meet within the community, are one of the most common DSD options. However, evidence about the quality of care (QoC) delivered in ART clubs is still limited. MATERIALS AND METHODS: We conducted a concurrent triangulation mixed-methods study as part of the Test & Treat project in northwest Tanzania. We surveyed QoC among stable clients and health care workers (HCW) comparing between clinics and clubs. Using a Donabedian framework we structured the analysis into three levels of assessment: structure (staff, equipment, supplies, venue), processes (time-spent, screenings, information, HCW-attitude), and outcomes (viral load, CD4 count, retention, self-worth). RESULTS: We surveyed 629 clients (40% in club) and conducted eight focus group discussions, while 24 HCW (25% in club) were surveyed and 22 individual interviews were conducted. Quantitative results revealed that in terms of structure, clubs fared better than clinics except for perceived adequacy of service delivery venue (94.4% vs 50.0%, p = 0.013). For processes, time spent receiving care was significantly more in clinics than clubs (119.9 vs 49.9 minutes). Regarding outcomes, retention was higher in the clubs (97.6% vs 100%), while the proportion of clients with recent viral load <50 copies/ml was higher in clinics (100% vs 94.4%). Qualitative results indicated that quality care was perceived similarly among clients in clinics and clubs but for different reasons. Clinics were generally perceived as places with expertise and clubs as efficient places with peer support and empathy. In describing QoC, HCW emphasized structure-related attributes while clients focused on processes. Outcomes-related themes such as improved client health status, self-worth, and confidentiality were similarly perceived across clients and HCW. CONCLUSION: We found better structure and process of care in clubs than clinics with comparable outcomes. While QoC was perceived similarly in clinics and clubs, its meaning was understood differently between clients. DSD catered to the individual needs of clients, either technical care in the clinic or proximate and social care in the club. Our findings highlight that both clinic and DSD care are required as many elements of QoC were individually perceived.

Chemoenzymatic enantioselective route to get (+) and (-) 4-acetoxy-azetidin-2-one by lipase-catalysed kinetic resolution and their applications.

4-Acetoxy-azetidin-2-one is an extremely useful intermediate widely applied for the synthesis of several biologically active ß-lactam compounds. However, it is available as a racemic mixture that could limit its application in the synthesis of enantiopure products. Herein we evaluated the use of lipases in a kinetic resolution (KR) process to finally obtain 4-acetoxy-zetidin-2-one as separated pure enantiomers. From a preliminary screening on a set of commercial enzymes, Pseudomonas fluorescens emerged as the most suitable lipase that allowed to obtain good conversions and excellent enantiomeric excesses. On the enantiomerically pure 4-acetoxy-azetidin-2-ones some nucleophilic substitutions and N-thio-alkylation reactions were tested in order to evaluate the stereochemical integrity at the C-4 position.

Beyond viral suppression: Quality of life among stable ART clients in a differentiated service delivery intervention in Tanzania.

BACKGROUND: With antiretroviral therapy, more people living with HIV (PLHIV) in resource-limited settings are virally suppressed and living longer. WHO recommends differentiated service delivery (DSD) as an alternative, less resource-demanding way of expanding HIV services access. Monitoring client's health-related quality of life (HRQoL) is necessary to understand patients' perceptions of treatment and services but is understudied in sub-Saharan Africa. We assessed HRQoL among ART clients in Tanzania accessing two service models. METHODS: Cross-sectional survey from May-August 2019 among stable ART clients randomly sampled from clinics and clubs in the Shinyanga region providing DSD and clinic-based care. HRQoL data were collected using a validated HIV-specific instrument-Functional Assessment of HIV infection (FAHI), in addition to socio-demographic, HIV care, and service accessibility data. Descriptive analysis of HRQoL, logistic regression and a stepwise multiple linear regression were performed to examine HRQoL determinants. RESULTS: 629 participants were enrolled, of which 40% accessed DSD. Similar HRQoL scores [mean (SD), p-value]; FAHI total [152.2 (22.2) vs 153.8 (20.6), p 0.687] were observed among DSD and clinic-based care participants. Accessibility factors contributed more to emotional wellbeing among DSD participants compared to the clinic-based care participants (53.4% vs 18.5%, p = < 0.001). Satisfactory (> 80% of maximum score) HRQoL scoring was associated with (OR [95% CI], p-value) being male (2.59 [1.36-4.92], p 0.004) among clinic participants and with urban residence (4.72 [1.70-13.1], p 0.001) among DSD participants. CONCLUSIONS: Similar HRQoL was observed in DSD and clinic-based care. Our research highlights focus areas to identify supporting interventions, ultimately optimizing HRQoL among PLHIV.

Selective Integrin Ligands Promote Cell Internalization of the Antineoplastic Agent Fluorouracil.

Drug conjugates consisting of an antineoplastic drug and a targeting receptor ligand could be effective to overcome the heavy side effects of unselective anticancer agents. To address this need, we report here the results of a project aimed to study agonist and antagonist integrin ligands as targeting head of molecular cargoes for the selective delivery of 5-fluorouracil (5-FU) to cancer or noncancer cells. Initially, two fluorescent ß-lactam-based integrin ligands were synthesized and tested for an effective and selective internalization mediated by α4ß1 or α5ß1 integrins in Jurkat and K562 cells, respectively. No cellular uptake was observed for both fluorescent compounds in HEK293 noncancerous control cells. Afterward, three conjugates composed of the ß-lactam-based integrin ligand, suitable linkers, and 5-FU were realized. The best compound E, acting as α5ß1 integrin agonist, is able to selectively deliver 5-FU into tumor cells, successfully leading to cancer cell death.

Therapeutic Peptides Targeting PPI in Clinical Development: Overview, Mechanism of Action and Perspectives.

Targeting protein-protein interactions (PPIs) has been recently recognized as an emerging therapeutic approach for several diseases. Up today, more than half a million PPI dysregulations have been found to be involved in pathological events. The dynamic nature of these processes and the involvement of large protein surfaces discouraged anyway the scientific community in considering them promising therapeutic targets. More recently peptide drugs received renewed attention since drug discovery has offered a broad range of structural diverse sequences, moving from traditionally endogenous peptides to sequences possessing improved pharmaceutical profiles. About 70 peptides are currently on the marked but several others are in clinical development. In this review we want to report the update on these novel APIs, focusing our attention on the molecules in clinical development, representing the direct consequence of the drug discovery process of the last 10 years. The comprehensive collection will be classified in function of the structural characteristics (native, analogous, heterologous) and on the basis of the therapeutic targets. The mechanism of interference on PPI will also be reported to offer useful information for novel peptide design.

Palladium Catalyst Recycling for Heck-Cassar-Sonogashira Cross-Coupling Reactions in Green Solvent/Base Blend.

The identification of a green, versatile, user-friendly, and efficient methodology is necessary to facilitate the use of Heck-Cassar-Sonogashira (HCS) cross-coupling reaction in drug discovery and industrial production in the pharmaceutical segment. The Heck-Cassar and Sonogashira protocols, using N-hydroxyethylpyrrolidone (HEP)/water/N,N,N',N'-tetramethyl guanidine (TMG) as green solvent/base mixture and sulfonated phosphine ligands, allowed to recycle the catalyst, always guaranteeing high yields and fast conversion under mild conditions, with aryl iodides, bromides, and triflates. No catalyst leakage or metal contamination of the final product were observed during the HCS recycling. To our knowledge, a turnover number (TON) up to 2375, a turnover frequency (TOF) of 158 h-1 , and a process mass intensity (PMI) around 7 that decreased around 3 after solvent, base, and palladium recovery, represent one of the best results to date using a sustainable protocol. The Heck-Cassar protocol using sSPhos was successfully applied to the telescoped synthesis of Erlotinib (TON: 1380; TOF: 46 h-1 ).

N-Thio-ß-lactams targeting L,D-transpeptidase-2, with activity against drug-resistant strains of Mycobacterium tuberculosis.

Effective treatment of tuberculosis is frequently hindered by the emerging antimicrobial resistance of Mycobacterium tuberculosis. The present study evaluates monocyclic ß-lactam compounds targeting the mycobacterial cell wall remodeling. Novel N-thio-ß-lactams were designed, synthesized, and characterized on the L,D-transpeptidase-2, a validated target in M. tuberculosis. The candidates were evaluated in biochemical assays identifying five compounds presenting target-specific kinetic constants equal or superior to meropenem, a carbapenem currently considered for tuberculosis therapy. Mass spectrometry in line with the crystal structures of five target-ligand complexes revealed that the N-thio-ß-lactams act via an unconventional mode of adduct formation, transferring the thio-residues from the lactam ring to the active-site cysteine of LdtMt2. The resulting stable adducts lead to a long-term inactivation of the target protein. Finally, the candidates were evaluated in vitro against a drug-susceptible and multidrug-resistant clinical isolates of M. tuberculosis, confirming the antimycobacterial effect of these novel compounds.

Strontium substituted hydroxyapatite with ß-lactam integrin agonists to enhance mesenchymal cells adhesion and to promote bone regeneration.

Multi-functionalization of calcium phosphates to get delivery systems of therapeutic agents is gaining increasing relevance for the development of functional biomaterials aimed to solve problems related to disorders of the muscolo-skeletal system. In this regard, we functionalized Strontium substituted hydroxyapatite (SrHA) with some ß-lactam integrin agonists to develop materials with enhanced properties in promoting cell adhesion and activation of intracellular signaling as well as in counteracting abnormal bone resorption. For this purpose, we selected two monocyclic ß-lactams on the basis of their activities towards specific integrins on promoting cell adhesion and signalling. The amount of ß-lactams loaded on SrHA could be modulated on changing the polarity of the loading solution, from 3.5-24 wt% for compound 1 and from 3.2-8.4 wt% for compound 2. Studies on the release of the ß-lactams from the functionalized SrHA in aqueous medium showed an initial burst followed by a steady-release that ensures a small but constant amount of the compounds over time. The new composites were fully characterized. Co-culture of human primary mesenchymal stem cells (hMSC) and human primary osteoclast (OC) demonstrated that the presence of ß-lactams on SrHA favors hMSC adhesion and viability, as well as differentiation towards osteoblastic lineage. Moreover, the ß-lactams were found to enhance the inhibitory role of Strontium on osteoclast viability and differentiation.

Ampicillin sodium: Isolation, identification and synthesis of the last unknown impurity after 60 years of clinical use.

Ampicillin, discovered in 1958, was the first broad spectrum semisynthetic penicillin introduced into the market. Despite its wide use not all the impurities have been identified to date. Herein, the last unknown impurity present in commercially available medicines was isolated and identified. This impurity that accounts up to 0.8 in area % by HPLC (EP 10.0) in the Reference Listed Drugs (RLD) was characterized and identified to be the 16-keto penicillin G. The structure was confirmed by comparison with a chemically synthesized sample. The determination of the Relative Response Factor (RRF) of the impurity respect to the parent drug allowed to recalculate the real amount that is consistently below the reporting threshold.

Combining Biologically Active ß-Lactams Integrin Agonists with Poly(l-lactic acid) Nanofibers: Enhancement of Human Mesenchymal Stem Cell Adhesion.

Regulating stem cell adhesion and growth onto functionalized biomaterial scaffolds is an important issue in the field of tissue engineering and regenerative medicine. In this study, new electrospun scaffolds of poly(l-lactic acid) (PLLA), as bioresorbable polymer, and ß-lactam compounds agonists of selected integrins, as functional components with cell adhesive properties, are designed. The new ß-lactam-PLLA scaffolds contribute significantly in guiding protein translation involved in human bone marrow mesenchymal stem cells (hBM-MSC) adhesion and integrin gene expression. Scanning electron microscopy, confocal laser scanning microscopy, and Western Blot analyses reveal that GM18-PLLA shows the best results, promoting cell adhesion by significantly driving changes in focal adhesion proteins distribution (ß1 integrin and vinculin) and activation (pFAK), with a notable increase of GM18-targets subunits integrin gene expression, α4 and ß1. These novel functionalized submicrometric fibrous scaffolds demonstrate, for the first time, the powerful combination of selective ß-lactams agonists of integrins with biomimetic scaffolds, suggesting a designed rule that could be suitably applied to tissue repair and regeneration.

Could Dissecting the Molecular Framework of ß-Lactam Integrin Ligands Enhance Selectivity?

By dissecting the structure of ß-lactam-based ligands, a new series of compounds was designed, synthesized, and evaluated toward integrins αvß3, α5ß1, and α4ß1. New selective ligands with antagonist or agonist activities of cell adhesion in the nanomolar range were obtained. The best agonist molecules induced significant adhesion of SK-MEL-24 cells and Saos-2 cells as a valuable model for osteoblast adhesion. These data could lead to the development of new agents to improve cellular osseointegration and bone regeneration. Molecular modeling studies on prototypic compounds and αvß3 or α5ß1 integrin supported the notion that ligand carboxylate fixing to the metal ion-dependent adhesion site in the ß-subunit can be sufficient for binding the receptors, while the aryl side chains play a role in determining the selectivity as well as agonism versus antagonism.

Novel insights into the chemistry of an old medicine: A general degradative pathway for penicillins from a piperacillin/tazobactam stability study.

Piperacillin is a broad spectrum beta-lactam antibiotic used in combination with tazobactam for hospital-related bacterial infections. The reconstituted solutions must respect the sub-visible and visible particles specifications. It was claimed that the reformulation containing EDTA/sodium citrate was able to control the formation of an insoluble impurity responsible for the formation of particulate matter observed using Ringer Lactate as diluent. The nature of the impurities formed during the degradative process of piperacillin/tazobactam combination has been herein investigated, by exploring the effect of added excipients and pH variations. The exact structure of the isolated dimeric impurity, the penicilloic acid-piperacillin dimer, was determined through complete characterization, allowing to propose a novel degradative general pathway for beta-lactam antibiotics. The presence of EDTA resulted unnecessary to contain the formation of the insoluble impurity, since the use of sodium citrate alone allowed to avoid this drawback. Finally, the proposed mechanism was successfully applied to the design of a novel, easy and high purity procedure for the synthesis of the acetylated penicilloic acid, known related substance of piperacillin.

Chiral ß-lactam-based integrin ligands through Lipase-catalysed kinetic resolution and their enantioselective receptor response.

Obtainment and testing of pure enantiomers are of great importance for bioactive compounds, because of the assessed implications of enantioselectivity in receptor-mediated responses. Herein we evaluated the use of biocatalysis to obtain enantiomerically pure ß-lactam intermediates further exploited in the synthesis of novel integrin ligands as single enantiomers. From a preliminary screening on a set of commercially available hydrolases, Burkholderia Cepacia Lipase (BCL) emerged as a suitable and highly performing enzyme for the kinetic resolution of a racemic azetidinone, key intermediate for the synthesis of novel agonists of integrins. Upon optimization of the biocatalytic protocol in terms of enzymes, acylating agents and procedures, the two ß-lactam enantiomers were obtained in excellent enantiomeric excesses (94% and 98% ee). Synthetic elaborations on the separated enantiomers allowed the synthesis of four chiral ß-lactams which were evaluated in cell adhesion assays on Jurkat cell line expressing α4ß1 integrin, and K562 cell line expressing α5ß1 integrin. Biological tests revealed that only (S)-enantiomers maintained the agonist activity of racemates with a nanomolar potency, and a specific enantio-recognition by integrin receptors was demonstrated.

Adherence to antiretroviral treatment among children and adolescents in Tanzania: Comparison between pill count and viral load outcomes in a rural context of Mwanza region.

BACKGROUND AND OBJECTIVES: Adherence to antiretroviral treatment is a key challenge for paediatric HIV care. Among children and adolescents living with HIV, lower levels of adherence have been reported compared to adults. Individual, caregiver-, health services-related and sociocultural factors were shown to impact on these outcomes. Study objectives were to assess adherence in a paediatric population in rural Tanzania comparing two measurement methods, and to investigate the association between virologic suppression and demographic, clinical, drug- and family-related factors. METHODS: This cross-sectional study was conducted among children and adolescents enrolled in Bukumbi HIV Care and Treatment Clinic (Misungwi district, Mwanza region) in the north of Tanzania, where the HIV prevalence is 7.2%. Adherence was measured through viral load and pill count. Kappa statistics assessed the level of agreement between the methods; bivariate and multivariable analyses identified factors independently associated with virologic suppression. RESULTS: N = 72 participants (n = 49 children; n = 23 adolescents) with a median age of eight years were enrolled. 62.5% and 65.3% of the individuals presented an optimal adherence according to viral load and pill count respectively, but among 40% viral load results diverged from the pill count method. In multivariable analysis, living outside Misungwi district and having CD4 counts above 500/µl were significantly associated with optimal adherence. CONCLUSION: Children and adolescents living with HIV in Mwanza show high rates of suboptimal adherence. The poor agreement between pill count and viral load results raises concerns about the interpretation of these measurements in clinical practice.