External validation of the DIAFORA system to predict lower-extremity amputations in a prospective Danish cohort.

Aim: A diabetes-related foot ulcer (DFU) is a major risk factor for lower-extremity amputation (LEA). To help clinicians predict the risk of LEA in people with DFU, the Diabetic Foot Risk Assessment (DIAFORA) system was developed but has never been externally validated.

Methods: In this study, 317 people presenting with a new DFU were included.

The value of loss of protective pain sensation in predicting a first ulceration of the foot in people with diabetes.

Aim: To determine both the risk of first ever ulcer (FEU) and its time to onset in a population which had loss of protective sensation (LOPS) in the foot either with or without loss of protective pain (LOPP).

Methods: People with diabetes and LOPS without history of FEU presenting in a specialist clinic were included. LOPP was diagnosed by reduced vibration perception and pain perception by using a pinprick simulator.

Synthesis of Enantiomerically Enriched Protected 2-Amino-, 2,3-Diamino- and 2-Amino-3-Hydroxypropylphosphonates.

Simple and efficient strategies for the syntheses of enantiomerically enriched functionalized diethyl 2-amino-, 2,3-diamino- and 2-amino-3-hydroxypropylphosphonates have been developed starting from, respectively, -protected (aziridin-2-yl)methylphosphonates, employing a regioselective aziridine ring-opening reaction with corresponding nucleophiles. Diethyl ()- and ()-2-(-Boc-amino)propylphosphonates were obtained via direct regiospecific hydrogenolysis of the respective enantiomer of ()- and ()--Boc-(aziridin-2-yl)methylphosphonates. N-Boc-protected ()- and ()-2,3-diaminopropylphosphonates were synthesized from ()- and ()--Bn-(aziridin-2-yl)methylphosphonates via a regiospecific ring-opening reaction with neat trimethylsilyl azide and subsequent reduction of ()- and ()-2-(-Boc-amino)-3-azidopropylphosphonates using triphenylphosphine.

HIV Proviral Burden, Genetic Diversity, and Dynamics in Viremic Controllers Who Subsequently Initiated Suppressive Antiretroviral Therapy.

Curing HIV will require eliminating the reservoir of integrated, replication-competent proviruses that persist despite antiretroviral therapy (ART). Understanding the burden, genetic diversity, and longevity of persisting proviruses in diverse individuals with HIV is critical to this goal, but these characteristics remain understudied in some groups. Among them are viremic controllers-individuals who naturally suppress HIV to low levels but for whom therapy is nevertheless recommended.

Synthesis of Enantiomerically Pure N-Boc-Protected 1,2,3-Triaminopropylphosphonates and 1,2-Diamino-3-Hydroxypropylphosphonates.

All possible isomers of 1,2,3-tri(--butoxycarbonylamino)propylphosphonate were synthesized from the respective diethyl [-(1-phenylethyl)]-1-benzylamino-2,3-epiiminopropylphosphonates via opening the aziridine ring with trimethylsilyl azide (TMSN) followed by hydrogenolysis in the presence of di--butyl dicarbonate (BocO). [-(1-phenylethyl)]-1-benzylamino-2,3-epiiminopropylphosphonates (1,2,1')- and (1,2,1')- were smoothly transformed into diethyl 3-acetoxy-1-benzylamino-2-[-(1-phenylethyl)amino]propylphosphonates (1,2,1')- and (1,2,1')-, respectively by the opening of the aziridine ring with acetic acid. Transformations of [-(1-phenylethyl)]-1-benzylamino-2,3-epiiminopropylphosphonates (1,2,1')- and (1,2,1')- into diethyl 3-acetoxy-1-benzylamino-2-[(1-phenylethyl)amino]propylphosphonates (1,2,1')- and (1,2,1')- were accompanied by the formation of ethyl {1-(-benzylacetamido)-3-hydroxy-2-[(1-phenylethyl)amino]propyl}phosphonate (1,2,1')- and (1,2,1')- and 3-(-benzylacetamido)-4-[-(1-phenylethyl)]amino-1,2-oxaphospholane (3,4,1')- and (3,4,1')- as side products.

-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds.

Since Garner's aldehyde has several drawbacks, first of all is prone to racemization, alternative three-carbon chirons would be of great value in enantioselective syntheses of natural compounds and/or drugs. This review article summarizes applications of -(1-phenylethyl)aziridine-2-carboxylates, -carbaldehydes and -methanols in syntheses of approved drugs and potential medications as well as of natural products mostly alkaloids but also sphingoids and ceramides and their 1- and 3-deoxy analogues and several hydroxy amino acids and their precursors. Designed strategies provided new procedures to several drugs and alternative approaches to natural products and proved efficiency of a 2-substituted -(1-phenylethyl)aziridine framework as chiron bearing a chiral auxiliary.

A Subset of Latency-Reversing Agents Expose HIV-Infected Resting CD4+ T-Cells to Recognition by Cytotoxic T-Lymphocytes.

Resting CD4+ T-cells harboring inducible HIV proviruses are a critical reservoir in antiretroviral therapy (ART)-treated subjects. These cells express little to no viral protein, and thus neither die by viral cytopathic effects, nor are efficiently cleared by immune effectors. Elimination of this reservoir is theoretically possible by combining latency-reversing agents (LRAs) with immune effectors, such as CD8+ T-cells.

Anti-APOBEC3G activity of HIV-1 Vif protein is attenuated in elite controllers.

Unlabelled: HIV-1-infected individuals who control viremia to below the limit of detection without antiviral therapy have been termed elite controllers (EC). Functional attenuation of some HIV-1 proteins has been reported in EC. The HIV-1 accessory protein Vif (virion infectivity factor) enhances viral infectivity through anti-retroviral factor apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3G (APOBEC3G) degradation; however, little is known regarding Vif function in EC.

Histone deacetylase inhibitors impair the elimination of HIV-infected cells by cytotoxic T-lymphocytes.

Resting memory CD4+ T-cells harboring latent HIV proviruses represent a critical barrier to viral eradication. Histone deacetylase inhibitors (HDACis), such as suberanilohydroxamic acid (SAHA), romidepsin, and panobinostat have been shown to induce HIV expression in these resting cells. Recently, it has been demonstrated that the low levels of viral gene expression induced by a candidate HDACi may be insufficient to cause the death of infected cells by viral cytopathic effects, necessitating their elimination by immune effectors, such as cytotoxic T-lymphocytes (CTL).

Reduced replication capacity of NL4-3 recombinant viruses encoding reverse transcriptase-integrase sequences from HIV-1 elite controllers.

Background: Identifying viral and host determinants of HIV-1 elite control may help inform novel therapeutic and/or vaccination strategies. Previously, we observed decreased replication capacity in controller-derived viruses suggesting that fitness consequences of human leukocyte antigen (HLA) class I-associated escape mutations in Gag may contribute to this phenotype. This study examines whether similar functional defects occur in Pol proteins of elite controllers.

Impaired replication capacity of acute/early viruses in persons who become HIV controllers.

Human immunodeficiency virus type 1 (HIV-1) controllers maintain viremia at <2,000 RNA copies/ml without antiretroviral therapy. Viruses from controllers with chronic infection were shown to exhibit impaired replication capacities, in part associated with escape mutations from cytotoxic-T-lymphocyte (CTL) responses. In contrast, little is known about viruses during acute/early infection in individuals who subsequently become HIV controllers.

HLA-associated viral mutations are common in human immunodeficiency virus type 1 elite controllers.

Elite controllers (EC) of human immunodeficiency virus type 1 (HIV-1) maintain viremia below the limit of detection without antiretroviral treatment. Virus-specific cytotoxic CD8(+) T lymphocytes are believed to play a crucial role in viral containment, but the degree of immune imprinting and compensatory mutations in EC is unclear. We obtained plasma gag, pol, and nef sequences from HLA-diverse subjects and found that 30 to 40% of the predefined HLA-associated polymorphic sites show evidence of immune selection pressure in EC, compared to approximately 50% of the sites in chronic progressors.

HLA-B57/B*5801 human immunodeficiency virus type 1 elite controllers select for rare gag variants associated with reduced viral replication capacity and strong cytotoxic T-lymphocyte [corrected] recognition.

Human immunodeficiency virus type 1 (HIV-1) elite controllers (EC) maintain viremia below the limit of commercial assay detection (<50 RNA copies/ml) in the absence of antiviral therapy, but the mechanisms of control remain unclear. HLA-B57 and the closely related allele B*5801 are particularly associated with enhanced control and recognize the same Gag(240-249) TW10 epitope. The typical escape mutation (T242N) within this epitope diminishes viral replication capacity in chronically infected persons; however, little is known about TW10 epitope sequences in residual replicating viruses in B57/B*5801 EC and the extent to which mutations within this epitope may influence steady-state viremia.

HLA-associated alterations in replication capacity of chimeric NL4-3 viruses carrying gag-protease from elite controllers of human immunodeficiency virus type 1.

Human immunodeficiency virus type 1 (HIV-1)-infected persons who maintain plasma viral loads of <50 copies RNA/ml without treatment have been termed elite controllers (EC). Factors contributing to durable control of HIV in EC are unknown, but an HLA-dependent mechanism is suggested by overrepresentation of "protective" class I alleles, such as B*27, B*51, and B*57. Here we investigated the relative replication capacity of viruses (VRC) obtained from EC (n = 54) compared to those from chronic progressors (CP; n = 41) by constructing chimeric viruses using patient-derived gag-protease sequences amplified from plasma HIV RNA and inserted into an NL4-3 backbone.

Telomerase activity of HIV-1-specific CD8+ T cells: constitutive up-regulation in controllers and selective increase by blockade of PD ligand 1 in progressors.

Exhaustion of virus-specific T cells may play an important role in the pathophysiology of chronic viral infections. Here, we analyzed telomere length and telomerase activity in HIV-1-specific CD8+ T cells from progressors or controllers to determine underlying molecular pathways of T-cell exhaustion and senescence. Telomere lengths of HIV-1-specific CD8+ T cells from progressors were significantly shorter compared with autologous cytomegalovirus (CMV)/Epstein-Barr virus (EBV)-specific CD8+ T cells or bulk CD8+ T cells, while telomere lengths from controllers significantly exceeded those of autologous bulk CD8+ T cells and reached a similar level as HIV-1-specific CD8+ T cells collected during primary HIV-1 infection.

Genetic characterization of human immunodeficiency virus type 1 in elite controllers: lack of gross genetic defects or common amino acid changes.

Despite reports of viral genetic defects in persons who control human immunodeficiency virus type 1 (HIV-1) in the absence of antiviral therapy, the extent to which such defects contribute to the long-term containment of viremia is not known. Most previous studies examining for such defects have involved small numbers of subjects, primarily focused on subjects expressing HLA-B57, or have examined single viral genes, and they have focused on cellular proviral DNA rather than plasma viral RNA sequences. Here, we attempted viral sequencing from 95 HIV-1 elite controllers (EC) who maintained plasma viral loads of <50 RNA copies/ml in the absence of therapy, the majority of whom did not express HLA-B57.

Structural and functional constraints limit options for cytotoxic T-lymphocyte escape in the immunodominant HLA-B27-restricted epitope in human immunodeficiency virus type 1 capsid.

Control of human immunodeficiency virus type 1 (HIV-1) by HLA-B27-positive subjects has been linked to an immunodominant CD8(+) cytotoxic T-lymphocyte (CTL) response targeting the conserved KK10 epitope (KRWIILGLNK(263-272)) in p24/Gag. Viral escape in KK10 typically occurs through development of an R(264)K substitution in conjunction with the upstream compensatory mutation S(173)A, and the difficulty of the virus to escape from the immune response against the KK10 epitope until late in infection has been associated with slower clinical progression. Rare alternative escape mutations at R(264) have been observed, but factors dictating the preferential selection of R(264)K remain unclear.

Genetic and immunologic heterogeneity among persons who control HIV infection in the absence of therapy.

Background: Spontaneous control of human immunodeficiency virus (HIV) infection has been documented in a minority of HIV-infected individuals. The mechanisms behind this outcome remain largely unknown, and a better understanding of them will likely influence future vaccine strategies.

Methods: HIV-specific T cell and antibody responses as well as host genetics were examined in untreated HIV-infected patients who maintain comparatively low plasma HIV RNA levels (hereafter, controllers), including those with levels of < 50 RNA copies/mL (elite controllers, n = 64), those with levels of 50-2000 copies/mL (viremic controllers, n = 60); we also examined HIV-specific T cell and antibody responses as well as host genetics for patients with levels of >10,000 copies/mL (chronic progressors, n = 30).

A viral CTL escape mutation leading to immunoglobulin-like transcript 4-mediated functional inhibition of myelomonocytic cells.

Viral mutational escape can reduce or abrogate recognition by the T cell receptor (TCR) of virus-specific CD8+ T cells. However, very little is known about the impact of cytotoxic T lymphocyte (CTL) epitope mutations on interactions between peptide-major histocompatibility complex (MHC) class I complexes and MHC class I receptors expressed on other cell types. Here, we analyzed a variant of the immunodominant human leukocyte antigen (HLA)-B2705-restricted HIV-1 Gag KK10 epitope (KRWIILGLNK) with an L to M amino acid substitution at position 6 (L6M), which arises as a CTL escape variant after primary infection but is sufficiently immunogenic to elicit a secondary, de novo HIV-1-specific CD8+ T cell response with an alternative TCR repertoire in chronic infection.

Structure-based design, synthesis, and biological evaluation of indomethacin derivatives as cyclooxygenase-2 inhibiting nitric oxide donors.

Indomethacin, a nonselective cyclooxygenase (COX) inhibitor, was modified in three distinct regions in an attempt both to increase cyclooxygenase-2 (COX-2) selectivity and to enhance drug safety by covalent attachment of an organic nitrate moiety as a nitric oxide donor. A human whole-blood COX assay shows the modifications on the 3-acetic acid part of the indomethacin yielding an amide-nitrate derivative 32 and a sulfonamide-nitrate derivative 61 conferred COX-2 selectivity. Along with their respective des-nitrate analogs, for example, 31 and 62, the nitrates 32 and 61 were effective antiinflammatory agents in the rat air-pouch model.

Selective depletion of high-avidity human immunodeficiency virus type 1 (HIV-1)-specific CD8+ T cells after early HIV-1 infection.

Human immunodeficiency virus type 1 (HIV-1)-specific CD8+ T cells in early infection are associated with the dramatic decline of peak viremia, whereas their antiviral activity in chronic infection is less apparent. The functional properties accounting for the antiviral activity of HIV-1-specific CD8+ T cells during early infection are unclear. Using cytokine secretion and tetramer decay assays, we demonstrated in intraindividual comparisons that the functional avidity of HIV-1-specific CD8+ T cells was consistently higher in early infection than in chronic infection in the presence of high-level viral replication.

Nef interference with HIV-1-specific CTL antiviral activity is epitope specific.

HIV-1 Nef and HIV-1-specific cytotoxic T lymphocytes (CTLs) have important and opposing roles in the immunopathogenesis of HIV-1 infection. Nef-mediated down-modulation of HLA class I on infected cells can confer resistance to CTL clearance, but the factors determining the efficiency of this process are unknown. This study examines the impact of Nef on the antiviral activity of several CTL clones recognizing epitopes from early and late HIV-1 proteins, restricted by HLA-A, -B, and -C molecules.

Synthesis and anti-inflammatory activity of a series of N-substituted naproxen glycolamides: nitric oxide-donor naproxen prodrugs.

A series of glycolamide naproxen prodrugs containing a nitrate group as a nitric oxide (NO) donor moiety has been synthesized. These compounds were evaluated for their anti-inflammatory activity, naproxen release, and gastric tolerance. Compounds 4a, 4b, 5a, 5b, 7b, and 7c exhibited anti-inflammatory activity equivalent to that of the parent NSAID, naproxen-Na, in the rat carrageenan paw edema model.

NMI-1182, a gastro-protective cyclo-oxygenase-inhibiting nitric oxide donor.

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat inflammation and to provide pain relief but suffer from a major liability concerning their propensity to cause gastric damage. As nitric oxide (NO) is known to be gastro-protective we have synthesized a NO-donating prodrug of naproxen named NMI-1182. We evaluated two cyclo-oxygenase (COX)-inhibiting nitric oxide donors (CINODs), NMI-1182 and AZD3582, for their ability to be gastro-protective compared to naproxen and for their anti-inflammatory activity.