Antiretroviral Drug Resistance in a Respondent-Driven Sample of HIV-Infected Men Who Have Sex With Men in Brazil

Background: There are few studies on HIV subtypes and primary and secondary antiretroviral drug resistance (ADR) in community-recruited samples in Brazil. We analyzed HIV clade diversity and prevalence of mutations associated with ADR in men who have sex with men in all five regions of Brazil. Methods: Using respondent-driven sampling, we recruited 3515 men who have sex with men in nine cities: 299 (9.5%) were HIV-positive; 143 subjects had adequate genotyping and epidemiologic data. Forty-four (30.8%) subjects were antiretroviral therapy-experienced (AE) and 99 (69.2%) antiretroviral therapy-naive (AN). We sequenced the reverse transcriptase and protease regions of the virus and analyzed them for drug resistant mutations using World Health Organization guidelines. Results: The most common subtypes were B (81.8%), C (7.7%), and recombinant forms (6.9%). The overall prevalence of primary ADR resistance was 21.4% (i.e. among the AN) and secondary ADR was 35.8% (i.e. among the AE). The prevalence of resistance to protease inhibitors was 3.9% (AN) and 4.4% (AE); to nucleoside reverse transcriptase inhibitors 15.0% (AN) and 31.0% (AE) and to nonnucleoside reverse transcriptase inhibitors 5.5% (AN) and 13.2% (AE). The most common resistance mutation for nucleoside reverse transcriptase inhibitors was 184V (17 cases) and for nonnucleoside reverse transcriptase inhibitors 103N (16 cases). Conclusions: Our data suggest a high level of both primary and secondary ADR in men who have sex with men in Brazil. Additional studies are needed to identify the correlates and causes of antiretroviral therapy resistance to limit the development of resistance among those in care and the transmission of resistant strains in the wider epidemic.

Effects of the association zidovudine plus ritonavir on the liver and kidneys of pregnant rats. Morphological and biochemical aspects

Purpose: To evaluate biochemical and morphological effects on rats submitted to three different doses of the association zidovudine and ritonavir administered throughout pregnancy. Methods: Forty pregnant EPM-1 Wistar rats weighing about 200 g were randomly divided into the control group (Ctr = drug vehicle control, n = 10) and three experimental ones which were treated with an oral solution of zidovudine/ritonavir (Exp1 = 10/20 mg/kg bw, n = 10; Exp2 = 30/60 mg/kg bw, n = 10; Exp3 = 90/180 mg/kg bw, n = 10) from `day 0` up to the 20th day of pregnancy. At term (20th day) the rats were anesthetized. Blood and fetal and maternal organ samples (livers and kidneys) were taken for morphological and biochemical analyses. Results: Upon histological examinations fetal livers and kidneys appeared normal. In contrast the maternal samples revealed structural alterations. Maternal kidneys of the three experimental groups exhibited progressive and dose-dependent histological alterations; liver alterations were detected only in Exp3. Blood levels of AST and ALT were not significantly different from the control group but urea and creatinine levels were lower in groups Exp3 and Exp1. Conclusions: The administration of zidovudine plus ritonavir throughout rat pregnancy can cause morphological as well as functional changes in maternal kidneys.

A single nucleotide deletion at the C1 inhibitor gene as the cause of hereditary angioedema: insights from a Brazilian family

Background: Hereditary angioedema is an autosomal dominant disease characterized by episodes of subcutaneous and submucosal edema. It is caused by deficiency of the C1 inhibitor protein, leading to elevated levels of bradykinin. More than 200 mutations in C1 inhibitor gene have been reported. The aim of this study was to analyze clinical features of a large family with an index case of hereditary angioedema and to determine the disease-causing mutation in this family. Methods: Family pedigree was constructed with 275 individuals distributed in five generations. One hundred and sixty-five subjects were interviewed and investigated for mutation at the C1 inhibitor gene. Subjects reporting a history of recurrent episodes of angioedema and/or abdominal pain attacks underwent evaluation for hereditary angioedema. Results: We have identified a novel mutation at the C1 inhibitor gene, c.351delC, which is a single-nucleotide deletion of a cytosine on exon 3, resulting in frameshift with premature stop codon. Sequencing analysis of the hypothetical truncated C1 inhibitor protein allowed us to conclude that, if transcription occurs, this protein has no biological activity. Twenty-eight members of the family fulfilled diagnostic criteria for hereditary angioedema and all of them presented the c.351delC mutation. Variation in clinical presentation and severity of disease was observed among these patients. One hundred and thirty-seven subjects without hereditary angioedema did not have the c.351delC mutation. Conclusion: The present study provides definitive evidence to link a novel genetic mutation to the development of hereditary angioedema in patients from a Brazilian family.

Interleukin-18 and interferon-gamma polymorphisms in Brazilian human immunodeficiency virus-1-infected patients presenting with lipodystrophy syndrome

Cytokines play important roles in the pathogenesis of lipodystrophy syndrome (LS). Single nucleotide polymorphisms (SNPs) at positions -607(C/A) and -137(C/G) in the promoter region of the interleukin-18 (IL-18) gene and at position +874(T/A) of the interferon-gamma (IFN-gamma) gene are related to the expression of these cytokines. To examine whether IL-18 and IFN-gamma polymorphisms are associated with LS, these SNPs were genotyped in 88 human immunodeficiency virus (HIV)-infected patients presenting LS, 79 HIV-infected without LS, and 133 healthy controls. The -607A allele, -607AA genotype, and -137G/-607A and -137C/-607A haplotypes in the IL-18 gene were over-represented in HIV patients presenting LS. The -137G/-607C haplotype was associated with protection against LS. These results indicate that the -607(C/A) SNP is associated with LS development in HIV-infected patients.

Inhibition of Neutrophil Migration by Hemopexin Leads to Increased Mortality Due to Sepsis in Mice

Rationale: The reduction of neutrophil migration to the bacterial focus is associated with poor outcome in sepsis. Objectives: The objective of this study was to identify soluble substances in the blood of septic mice that inhibit neutrophil migration. Methods: A pool of serum obtained from mice 2 hours after the induction of severe sepsis by cecal ligation and puncture inhibited the neutrophil migration. The proteins with inhibitory activity on neutrophil migration were isolated by Blue-Sepharose chromatography, high-performance liquid chromatography, and electrophoresis, and identified by mass spectrometry. Measurements and Main Results: Hemopexin was identified as the serum component responsible for the inhibition of neutrophil migration. In sepsis, the pretreatment of wild-type mice with hemopexin inhibited neutrophil migration to the focus of infection and decreased the survival rate from 87.5 to 50.0%. Hemopexin-null mice subjected to severe sepsis presented normal neutrophil migration, low bacteremia, and an improvement of 40% in survival rate. Moreover, hemopexin inhibited the neutrophil chemotaxis response evoked by C5a or macrophage inflammatory protein-2 and induced a reduction of CXCR2 and L-selectin as well as the up-regulation of CD11b expression in neutrophil membranes. The inhibitory effect of hemopexin on neutrophil chemotaxis was prevented by serine protease inhibitors or ATP. In addition, serum levels of ATP were decreased 2 hours after severe sepsis. Conclusions: These data demonstrate for the first time the inhibitory role of hemopexin in neutrophil migration during sepsis and suggest that the therapeutic inhibition of hemopexin or its protease activity could improve neutrophil migration to the focus of infection and survival in sepsis.

Oral lesions and immune reconstitution syndrome in HIV+/AIDS patients receiving highly active antiretroviral therapy. Epidemiological evidence

Objective: To determine whether opportunistic oral infections associated to HIV infection (OOI-HIV) are found in HIV+/AIDS patients with immune reconstitution related to highly active antiretroviral therapy (HAART). Methods. From among 1100 HIV+/AIDS patients (Service of Internal Medicine, Carlos Haya Hospital, Malaga, Spain) subjected to review of the oral cavity between January 1996 and May 2007, we identified those examined in 1996 and which were again examined between 1997 and 2007, and were moreover receiving HAART. The following data were collected: age, gender, form of contagion, antiretroviral therapy at the time of review, number of CD4+ lymphocytes/ml, and viral load (from 1997 onwards). We identified those subjects with an increase in CD4+ lymphocytes/ ml associated to HAART, and classified them as subjects with quantitative evidence of immune reconstitution (QEIR). Among these individuals with QEIR we moreover identified those with undetectable viral loads (QEIR+VL), and differentiated those patients with an increase in CD4+ lymphocytes > 500/ml (QEIRm+VL). In each group we determined the prevalence of OOI-HIV, following the diagnostic recommendations of the EC-Clearinghouse (CDC-Atlanta, USA - WHO). In addition, we analyzed the prevalence of OOI-HIV in the different groups in relation to the duration of HAART. Results. A total of 86 subjects were included (44 females and 42 males; 19 heterosexuals, 34 male homosexuals, and 33 intravenous drug abusers). Forty-two patients showed QEIR: 21 belonged to the QEIR+VL group, and 17 conformed the QEIRm+VL group. The prevalence of OOI-HIV per group was as follows: QEIR = 54.8%; QEIR+VL = 33%; QEIRm+VL = 35%. The most prevalent lesion in all groups was erythematous candidiasis. OOI-HIV increased with the duration of HAART (p=0.008), and were seen to be dependent upon late appearance of the mycotic lesions ( after 24 months under HAART). Conclusions: It is suggested that opportunistic oral infections associated to HIV infection form part of the clinical picture of immune reconstitution inflammatory syndrome, though such infections are of late onset.

Oral manifestations after immune reconstitution in HIV patients on HAART

In order to verify possible association between immune reconstitution inflammatory syndrome (IRIS) and oral manifestations (OMs), we selected AIDS patients who had low CD4 count before the initiation of highly active antiretroviral therapy (HAART) and who returned three months later for therapy evaluation. The oral lesions observed three months after the initiation of HAART were evaluated and associated with the type of antiretroviral therapy (ART), CD4 count and HIV-RNA load levels (before and three months after HAART initiation). A total of 105 patients matched the selected criteria. Immune reconstitution (IR) was identified in 35.2%. Among these patients, the mean CD4 cell count rose from 105.97 to 330.29 and the mean viral load dropped from 168.005 (log 5.22) to 21.852 (log 4.33). There was no significant difference in age (P=0.78), sex (P=0.41) or previous history of ART (P=0.55) between IR and non-IR patients. In the IR group, the most common OM was. parotid enlargement (57.14%) (P=0.619), whereas in the non-IR group candidiasis (46.15%) was the most common OM. The results of our study suggest that the parotid gland enlargement found in the studied population might be an IRIS event, as it was found in patients with IR three months after the initiation of HAART.

State of the art etch-and-rinse adhesives

Objectives: The aim of this study was to explore the therapeutic opportunities of each step of 3-step etch-and-rinse adhesives. Methods: Etch-and-rinse adhesive systems are the oldest of the multi-generation evolution of resin bonding systems. In the 3-step version, they involve acid-etching, priming and application of a separate adhesive. Each step can accomplish multiple goals. Acid-etching, using 32-37% phosphoric acid (pH 0.1-0.4) not only simultaneously etches enamel and dentin, but the low pH kills many residual bacteria. Results: Some etchants include anti-microbial compounds such as benzalkonium chloride that also inhibits matrix metalloproteinases (MMPs) in dentin. Primers are usually water and HEMA-rich solutions that ensure complete expansion of the collagen fibril meshwork and wet the collagen with hydrophilic monomers. However, water alone can re-expand dried dentin and can also serve as a vehicle for protease inhibitors or protein cross-linking agents that may increase the durability of resin-dentin bonds. In the future, ethanol or other water-free solvents may serve as dehydrating primers that may also contain antibacterial quaternary ammonium methacrylates to inhibit dentin MMPs and increase the durability of resin-dentin bonds. The complete evaporation of solvents is nearly impossible. Significance: Manufacturers may need to optimize solvent concentrations. Solvent-free adhesives can seal resin-dentin interfaces with hydrophobic resins that may also contain fluoride and antimicrobial compounds. Etch-and-rinse adhesives produce higher resin-dentin bonds that are more durable than most 1 and 2-step adhesives. Incorporation of protease inhibitors in etchants and/or cross-linking agents in primers may increase the durability of resin-dentin bonds. The therapeutic potential of etch-and-rinse adhesives has yet to be fully exploited. (C) 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

A genetic polymorphism of matrix metalloproteinase 9 (MMP-9) affects the changes in circulating MMP-9 levels induced by highly active antiretroviral therapy in HIV patients

We examined whether two functional polymorphisms (g.-1562C>T and g.-90(CA)14-24) in the matrix metalloproteinase (MMP)-9 gene or MMP-9 haplotypes affect the circulating levels of pro-MMP-9 and pro-MMP-9/TIMP-1 (tissue inhibitor of metalloproteinase-1) ratios in AIDS patients, and modulate alterations in these biomarkers after highly active antiretroviral therapy (HAART). We studied 82 patients commencing HAART. Higher pro-MMP-9 concentrations and pro-MMP-9/TIMP-1 ratios were found in CT/TT patients compared with CC patients. HAART decreased pro-MMP-9 levels and pro-MMP-9/TIMP-1 ratios in CT/TT patients, it did not modify pro-MMP-9 levels and it increased pro-MMP-9/TIMP-1 ratios in CC patients. The g.-90(CA)14-24 polymorphism, however, produced no significant effects. Moreover, we found no significant differences in HAART-induced changes in plasma pro-MMP-9, TIMP-1 and pro-MMP-9/TIMP-1 ratios when different MMP-9 haplotypes were compared. These findings suggest that the g.-1562C>T polymorphism affects pro-MMP-9 levels in patients with AIDS and modulates the alterations in pro-MMP-9 levels caused by HAART, thus possibly affecting the risk of cardiovascular complications. The Pharmacogenomics Journal (2009) 9, 265-273; doi: 10.1038/tpj.2009.13; published online 21 April 2009

Clinically significant drug interactions with agents specific for migraine attacks

The drugs which provide specific relief from migraine attacks, the ergopeptides (ergotamine and dihydroergotamine) and the various 'triptans' (notably sumatriptan), are often prescribed for persons already taking various migraine preventative agents, and sometimes drugs for other indications. As a result, migraine-specific drugs may become involved in drug-drug interactions. The migraine-specific drugs all act as agonists at certain subclasses of serotonin (5-hydroxytryptamine; 5-MT) receptor, particularly those of the 5-HT1D subtype, and produce vasoconstriction through these receptor-mediated mechanisms. The oral bioavailabilities of these drugs, particularly those of the ergopeptides, are often incomplete, due to extensive presystemic metabolism. As a result, if migraine-specific agents are coadministered with drugs with vasoconstrictive properties, or with drugs which inhibit the metabolism of the migraine-specific agents, there is a risk of interactions occurring which produce manifestations of excessive vasoconstriction. This can also occur through pharmacodynamic mechanisms, as when ergopeptides or triptans are coadministered with methysergide or propranolol (although a pharmacokinetic element may apply in relation to the latter interaction), or if one migraine-specific agent is used shortly after another. When egopeptide metabolism is inhibited by the presence of macrolide antibacterials, particularly troleandomycin and erythromycin, the resultant interaction can produce ergotism, sometimes leading to gangrene. Similar pharmacokinetic mechanisms, with their vasoconstrictive consequences, probably apply to combination of the ergopeptides with HIV protease inhibitors (indinavir and ritonavir), heparin, cyclosporin or tacrolimus. Inhibition of triptan metabolism by monoamine oxidase A inhibitors, e.g. moclobemide, may raise circulating triptan concentrations, although this does not yet seem to have led to reported clinical problems. Caffeine may cause increased plasma ergotamine concentrations through an as yet inadequately defined pharmacokinetic interaction. However, a direct antimigraine effect of caffeine may contribute to the claimed increased efficacy of ergotamine-caffeine combinations in relieving migraine attacks. Serotonin syndromes have been reported as probable pharmacodynamic consequences of the use of ergots or triptans in persons taking serotonin reuptake inhibitors. There have been two reports of involuntary movement disorders when sumatriptan has been used by patients already taking loxapine. Nearly all the clinically important interactions between the ergopeptide antimigraine agents and currently marketed drugs are likely to have already come to notice. In contrast, new interactions involving the triptans are likely to be recognised as additional members of this family of drugs, with their different patterns of metabolism and pharmacokinetics, are marketed.

Macrocycles mimic the extended peptide conformation recognized by aspartic, serine, cysteine and metallo proteases

It has been previously demonstrated that aspartic, serine, metallo and cysteine proteases bind to their inhibitors and substrate analogues in a single conformation, the saw-tooth or extended beta-strand. Consequently a generic approach to the development of protease inhibitors is the use of constraints that conformationally restrict putative inhibitor molecules to an extended form. In this way the inhibitor is pre-organized for binding to a protease and does not need to rearrange its structure. One constraining device that has proven to be effective for such pre-organization is macrocyclization. This article illustrates the general principle that macrocycles, especially those composed of 3-4 amino acids and usually 13-17 ring atoms, can effectively mimic the extended conformation of short peptide sequences. Such structure-stabilising macrocycles are stable to degradation by proteases, valuable components of potent protease inhibitors, and in many cases they are also bioavailable.

Solution structure of BSTI: A new trypsin inhibitor from skin secretions of Bombina bombina

The three-dimensional solution structure of BSTI, a trypsin inhibitor from the European frog Bombina bombina, has been solved using H-1 NMR spectroscopy. The 60 amino acid protein contains five disulfide bonds, which were unambiguously determined to be Cvs (4-38), Cys (13-34), Cys (17-30), Cys (21-60), and Cys (40-54) by experimental restraints and subsequent structure calculations. The main elements of secondary structure are four beta -strands, arranged as two small antiparallel beta -sheets, The overall fold of BSTI is disk shaped and is characterized by the lack of a hydrophobic core. The presumed active site is located on a loop comprising residues 21-34, which is a relatively disordered region similar to that seen in many other protease inhibitors. However, the overall fold is different to other known protease inhibitors with the exception of a small family of inhibitors isolated from nematodes of the family Ascaris and recently also from the haemolymph of Apis mellifera. BSTI may thus be classified as a new member of this recently discovered family of protease inhibitors.

A family of textilinin genes, two of which encode proteins with antihaemorrhagic properties

Two peptides, textilinins 1 and 2, isolated from the venom of the Australian common brown snake, Pseudonaja textilis textilis, are effective in preventing blood loss. To further investigate the potential of textilinins as anti-haemorrhagic agents, we cloned cDNAs encoding these proteins. The isolated full-length cDNA (430 bp in size) was shown to code for a 59 amino acid protein, corresponding in size to the native peptide, plus an additional 24 amino acid propeptide. Six such cDNAs were identified, differing in nucleotide sequence in the coding region but with an identical propeptide. All six sequences predicted peptides containing six conserved cysteines common to Kunitz-type serine protease inhibitors. When expressed as glutathione S-transferase (GST) fusion proteins and released by cleavage with thrombin, only those peptides corresponding to textilinin 1 and 2 were active in inhibiting plasmin with K-i values similar to those of their native counterparts and in binding to plasmin less tightly than aprotinin by two orders of magnitude. Similarly, in the mouse tail vein blood loss model only recombinant textilinin 1 and 2 were effective in reducing blood loss. These recombinant textilinins have potential as therapeutic agents for reducing blood loss in humans, obviating the need for reliance on aprotinin, a bovine product with possible risk of transmissible disease, and compromising the fibrinolytic system in a less irreversible manner.

Secretory pathway of trypanosomatid parasites

The Trypanosomatidae comprise a large group of parasitic protozoa, some of which cause important diseases in humans. These include Tryanosoma brucei (the causative agent of African sleeping sickness and nagana in cattle), Trypanosoma cruzi (the causative agent of Chagas' disease in Central and South America), and Leishmania spp. (the causative agent of visceral and [muco]cutaneous leishmaniasis throughout the tropics and subtropics). The cell surfaces of these parasites are covered in complex protein- or carbohydrate-rich coats that are required for parasite survival and infectivity in their respective insect vectors and mammalian hosts. These molecules are assembled in the secretory pathway. Recent advances in the genetic manipulation of these parasites as well as progress with the parasite genome projects has greatly advanced our understanding of processes that underlie secretory transport in trypanosomatids. This article provides an overview of the organization of the trypanosomatid secretory pathway and connections that exist with endocytic organelles and multiple lytic and storage vacuoles. A number of the molecular components that are required for vesicular transport have been identified, as have some of the sorting signals that direct proteins to the cell surface or organelles it? the endosome-vacuole system. Finally, the subcellular organization of the major glycosylation pathways in these parasites is reviewed. Studies on these highly divergent eukaryotes provide important insights into the molecular processes underlying secretory transport that arose very early in eukaryotic evolution. They also reveal unusual or novel aspects of secretory), transport and protein glycosylation that may be exploited in developing new antiparasite drugs.

Metabolic changes associated with antiretroviral therapy in HIV-positive patients

OBJECTIVE: To evaluate metabolic changes associated with highly active antiretroviral therapy (HAART) in HIV-positive patients, and to identify risk factors associated. METHODS: Retrospective study that included 110 HIV-positive patients who where on HAART in the city of Porto Alegre (Southern Brazil) between January 2003 and March 2004. Data on demographic variables, cigarette smoking, diabetes mellitus, cholesterol and triglyceride levels, stage of HIV infection, antiretroviral therapy and HCV coinfection were collected. General linear models procedure for repeated measures was used to test the interaction between HAART and HCV coinfection or protease inhibitor treatment. RESULTS: Total cholesterol, triglycerides, and glucose levels significantly increased after receiving HAART (p<0.001 for all variables), but no interaction with protease inhibitors was seen for total cholesterol, glucose and triglyceride levels (interaction treatment*protease inhibitors p=0.741, p=0.784, and p=0.081, respectively). An association between total cholesterol levels and HCV coinfection was found both at baseline and follow-up (effect of HCV coinfection, p=0.011). Glucose levels were increased by HAART (treatment effect, p=0.036), but the effect was associated to HCV coinfection (treatment*HCV effect, p=0.018). Gender, smoking habit, intravenous drug use and age were not significantly associated with cholesterol, triglyceride and glucose changes. CONCLUSIONS: HCV-infected patients at baseline were significantly less likely to develop hypercholesterolemia. The results provide further evidence of the role of HAART for the development of metabolic disturbances.