Hepatitis C virus genotypes in hemodialysis patients in Angola

To our knowledge, there are no published data on hepatitis C virus (HCV) genotypes in Angola. This study aimed at assessing the distribution of HCV genotypes in seropositive hemodialysis patients in Luanda. Among 51 HCV-positive subjects included, viremia was detected in 27 (53%). HCV genotyping was performed by bidirectional sequencing of the 5'-untranslated region by the Sanger method. HCV genotype 4 was largely predominant (20 cases; 74%), followed by genotypes 1b (5 cases; 18.5%), 1a and 2 (one case each; 3.7%). These results suggest that the distribution of HCV genotypes in Angola is similar to that reported from other Central African countries.     

High levels of serum glycans monovalent IgG immune complexes detected by dissociative ELISA in experimental visceral leishmaniasis

Visceral leishmaniasis (VL) is epidemic in Brazil with an increasing incidence of human cases and canine reservoirs, with host hypergammaglobulinemia. Conventional enzyme-linked immunosorbent assay (cELISA) based on several parasitic antigens is the main method for diagnosis and indication of treatment. Dissociative ELISA (dELISA) uses acidic treatment to free immunoglobulin G (IgG) from immune complexes, and its use revealed a significant positive fraction of suspected cases with negative serology. Looking for small molecules or haptens that block IgG antibodies, we purified by molecular exclusion chromatography, 1000–3000 MW molecules from promastigote soluble extract, mostly oligosaccharides comprising 6–13 sugar residues using MALDI-TOF analysis. Glycan-BSA complex (GBC) was constructed by conjugating promastigote glycans to BSA molecules, allowing their use in the solid support in cELISA or dELISA. Sera from experimentally infected hamsters showed higher levels of blocked monomeric IgG during infection, mostly against GBC, which was also present in lower concentrations in the promastigote soluble extract dELISA. Those data show that most of the specific monomeric IgG in serum are blocked by haptens composed by glycans produced by the parasite, better detected in the high dilution of sera in the dELISA assays. dELISA is a useful technique for detecting blocked monomeric antibodies that could have difficult clearance from blood, which could result in hypergammaglobulinemia.     

HIV-1-specific cytolytic T-lymphocyte activity correlates with lower viral load, higher CD4 count, and CD8+CD38-DR- phenotype: comparison of statistical methods for measurement.

OBJECTIVES: The objective of this study was to use novel statistical methods to determine the correlation between HIV-1-specific cytolytic T-lymphocyte (CTL) activity and HIV-1 plasma viral load, in a blinded study of HIV-infected patients at various stages of clinical disease. METHODS: Peripheral blood mononuclear cells (PBMC) were collected and stored at enrollment and 2 weeks later, from 15 HIV-infected individuals who were receiving stable antiretroviral therapy for the previous 6 weeks and during the study period. HIV-1-specific CTL activity was measured using an antigen-specific PBMC in vitro stimulation method. Measurements of plasma viral load, as well as CD4+ and CD8+ T lymphocytes expressing T-cell activation markers (DR and CD38) were also performed at each time point. CTL activity was quantified using three separate statistical methods: area under the net HIV-specific lysis curve (AUC), lytic units (LU20), and linear regression (LR) of net HIV-specific lysis. RESULTS: HIV-1 nef-, pol- and gag-specific CTL activity (AUC method) was significantly higher in subjects with a plasma viral load < or = 30,000 RNA copies/ml, than in those with viral load >30,000 RNA copies/ml. When plasma viral load was analyzed as a continuous variable, there was a strong correlation between higher CTL activity and lower viral load for nef (r2 = .77; p < .001), pol (r2 = .63; p < .001) and gag (r2 = 0.75; p < .001) targets by the AUC, but not for the LU20 analysis. Using the LR analysis, which is less dependent on in vitro PBMC growth than the AUC analysis, an independent association was demonstrated between nef- and gag-specific CTL activity and lower viral load. Measurement of CTL activity was also significantly correlated with a higher percentage of circulating CD8+DR-CD38- T lymphocytes. CONCLUSIONS: In this blinded study using an in vitro stimulation of frozen PBMC, higher HIV-1 nef-, pol-, and gag-specific CTL activity correlated with lower plasma viral load, particularly in patients with a CD4 count <500 cells/mm3. Two new statistical methods for estimating CTL activity, AUC and LR analyses, were superior to the standard lytic unit (LU20) method for demonstrating this correlation. These data also demonstrated that higher circulating CD8+ T lymphocytes with a DR-CD38-phenotype, correlate with a lower plasma viral and load and higher HIV-specific CTL activity. This suggests that lymphocytes with this double-negative phenotype may include circulating HIV-specific CD8+ CTL.     

Polymorphism of the thiopurine S-methyltransferase gene in African- Americans

The molecular basis for the genetic polymorphism of thiopurine S - methyltransferase (TPMT) has been estab-lished for Caucasians, but it remains to be elucidated in African populations. In the current study, we determined TPMT genotypes in a population of 248 African-Americans and compared it with allele frequencies in 282 Caucasian Americans. TPMT genotype was determined in all individuals with TPMT activity indicative of a heterozygous genotype (</=10.1 U/ml pRBC, n = 23African- Americans, n = 21 Caucasians) and a control group with TPMT activity indicative of a homozygous wild-type genotype (>10.2 U/ml pRBC, n = 23 African-Americans, n = 21 Caucasians). No mutant alleles were found in the high activity control groups. The overall mutant allele frequencies were similar in African-Americans and Caucasians (4.6 and 3.7% of alleles, respectively). However, while TPMT*3C was the most prevalent mutant allele in African-Americans (52.2% of mutant alleles), it represented only 4.8% of mutant alleles in Caucasians ( P < 0.001). In contrast, TPMT*3A and TPMT*2 were less common in African-Americans (17.4 and 8.7% of mutant alleles), whereas TPMT*3A was the most prevalent mutant allele in Caucasians (85.7% of mutant alleles). A novel allele ( TPMT*8 ), containing a single nucleotide transition (G644A), leading to an amino acid change at codon 215 (Arg-->His), was found in one African-American with intermediate activity. These data indicate that the same TPMT mutant alleles are found in American black and white populations, but that the predominant mutant alleles differ in these two ethnic groups.      

New rules for phytopharmaceutical drug registration in Brazil.

Although it is among the ten largest pharmaceutical markets in the world and has the most diverse flora, few efforts have been made in Brazil in order to assure legal rules, which are able to provide phytotherapeutical products with efficacy, safety and constant quality. Only in the last 3 years has the Ministry of Health convened an expert commission to evaluate the existent legal requirements for such products and to provide modern and effective legislation. The results of this work and the consequences of its implementation are discussed in this article.     

Vertical one-and-a-half syndrome in a patient with pecheron artery ischemia: A case report

Vertical one-and-a-half syndrome (VOHS) is an uncommon presentation resulting from a unilateral thalamomesencephalic stroke with involvement of the rostral interstitial nucleus of the medial longitudinal fasciculus and posterior commissure. The artery of Percheron (aPe) is a branch of the posterior cerebral artery (PCA) and it is a variant that arises as a solitary trunk supplying both medial thalami and upper midbrain. A 78-year-old female patient, presented at the hospital emergency with approximately 12 hours of sudden onset of diplopia, associated with dizziness. Neurological exam revealed torsional nystagmus associated with bilateral upgaze palsy with limitation of infraduction on the left. We describe a rare case of VOHS associated with ischemic alterations at the MRI suggesting an aPe impairment. The conjugate gaze control lies anatomically at the midbrain at the central nervous system (CNS). This report describes a rare type of VOHS and brings a new insight on a possible aPe topography possibly causing this clinical presentation.     

NK Cell Activity in the Presence of IL-12 Is a Prognostic Assay to Neoadjuvant Chemotherapy in Cervical Cancer

Objective. Little is known about the impact of neoadjuvant chemotherapy on cell-mediated immunity in patients with advanced cervical cancers.Patients and methods. We have studied 24 patients with advanced cervical cancer submitted to neoadjuvant chemotherapy (CT) using cis-platinum (100 mg/m²/cycle) and bleomycin (30 mg/cycle). The cell-mediated immunity parameters available before and after CT were NK cells, CD4⁺/CD28 and CD8⁺/CD28 T-lymphocyte numbers, PBMC cytotoxicity, and modification of this parameter with “in vitro” addition of IL-12.Results. The number of NK cells was higher before CT (P < 0.008) in 13 patients who presented a good clinical response to treatment, compared to 11 patients with a poor clinical response. In addition, PBMC cytotoxicity (P < 0.001), CD4⁺ and CD8⁺ T-lymphocyte values (P < 0.0047), and CD8⁺/CD28⁺ cells were also higher in the group with a good response compared with the group with a poor response. Addition of IL-12 to the medium increased the lytic capacity of PBMC after CT only in the group with a good clinical response (P < 0.05).Conclusions. NK cell numbers, CD8⁺ T-cell levels, and CD8⁺/CD28⁺ cell levels can be used as prognostic factors before CT. Our results suggest that patients with a poor response have lower lytic activity per NK cell and are refractory to IL-12 stimulation, probably as a result of the reduced expression of IL-12 receptors or of an intracellular defect in the mechanism of transduction. These observations also provide support for human clinical trials of IL-12 and neoadjuvant CT in patients with cervical cancer.     

Structural Covariance of Cortical Gyrification at Illness Onset in Treatment Resistance: A Longitudinal Study of First-Episode Psychoses

Treatment resistance (TR) in patients with first-episode psychosis (FEP) is a major cause of disability and functional impairment, yet mechanisms underlying this severe disorder are poorly understood. As one view is that TR has neurodevelopmental roots, we investigated whether its emergence relates to disruptions in synchronized cortical maturation quantified using gyrification-based connectomes. Seventy patients with FEP evaluated at their first presentation to psychiatric services were followed up using clinical records for 4 years; of these, 17 (24.3%) met the definition of TR and 53 (75.7%) remained non-TR at 4 years. Structural MRI images were obtained within 5 weeks from first exposure to antipsychotics. Local gyrification indices were computed for 148 contiguous cortical regions using FreeSurfer; each subject’s contribution to group-based structural covariance was quantified using a jack-knife procedure, providing a single deviation matrix for each subject. The latter was used to derive topological properties that were compared between TR and non-TR patients using a Functional Data Analysis approach. Compared to the non-TR patients, TR patients showed a significant reduction in small-worldness (Hedges’s g = 2.09, P < .001) and a reduced clustering coefficient (Hedges’s g = 1.07, P < .001) with increased length (Hedges’s g = −2.17, P < .001), indicating a disruption in the organizing principles of cortical folding. The positive symptom burden was higher in patients with more pronounced small-worldness (r = .41, P = .001) across the entire sample. The trajectory of synchronized cortical development inferred from baseline MRI-based structural covariance highlights the possibility of identifying patients at high-risk of TR prospectively, based on individualized gyrification-based connectomes.     

Apical Sealing Ability of Two Calcium Silicate-Based Sealers Using a Radioactive Isotope Method: An In Vitro Apexification Model

The aim of this study was to evaluate and compare the sealing ability of two calcium silicate-based sealers (TotalFill BC RRM Fast Set Putty and White ProRoot MTA) when used as apical plugs in immature teeth through nuclear medicine. Single-rooted extracted teeth (n = 34) had their crowns and root tip sectioned to obtain 14 mm long root segments to simulate an in vitro apexification model. Were created two experimental groups, namely MTA (n = 12) and BC (n = 12), and two control groups, PG (positive group, n = 5) and NG (negative group, n = 5). On the 4th day after placing the respective apical plug, the apical portions of the teeth were submerged in a solution of sodium pertechnetate (^99mTcNaO₄) for 3 h. Statistical analysis showed a significant difference between the MTA group and the controls (p < 0.05). The BC group had a significant difference regarding the negative control (p < 0.001) but showed no statistical significance regarding the positive control (p = 0.168). There was a statistically significant difference (p = 0.009) between the BC group (7335.8 ± 2755.5) and the MTA group (4059.1 ± 1231.1), where the last showed less infiltration. Within the limitations of this study, White ProRoot MTA had a significantly better sealing ability than TotalFill BC RRM Fast Set Putty.     

Complexation between hydrogensulfated fullerenol and poly(4‐vinylpyridine)

A fullerene (C₆₀) derivative, hydrogensulfated fullerenol, has been complexed with poly(4‐vinylpyridine) (P4VPy) through a supramolecular approach. The complexes are formed by mixing the N,N‐dimethylformamide (DMF) solutions of P4VPy and hydrogensulfated fullerenol with multiple —OSO₃H groups. Glass transition temperatures can not be detected in all complexes due to the strong interaction between the two components. Both Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy demonstrated the ionic nature of the interaction in the complexes.