Silver-modified nitrogen-doped graphene quantum dots as a sensor for formaldehyde in milk using headspace micro-extraction on a single-drop of aqueous nanoparticles dispersion.

BACKGROUND: Fraudulent practices used to distort the quality of milk and derivatives include the addition of formaldehyde. RESULTS: A formaldehyde sensor was developed based on the luminescence of newly proposed N-doped graphene quantum dots modified with silver (N-GQDs-Ag) that were prepared using a simple method. A microdroplet of the nanoparticle dispersion was used to collect formaldehyde vapor by headspace single-drop micro-extraction (HS-SDME). After, the microdroplet was diluted in water, the nanoparticle photoluminescence quenching, caused by the analyte, was measured. The strong luminescent quenching allowed a detection limit at 1.7 × 10-4% w/v. Response was selective towards formaldehyde. SIGNIFICANCE: The method was effective and a cost-effective method for screening analysis of milk samples with matrix interferences minimized due to the nature of nanoparticle (prepared using Tollen's reagent) and due to the probing at the headspace of the sample cell. Results were statistically similar to those obtained using liquid chromatography.

COVID-19 cross-sectional study in Maricá, Brazil: The impact of vaccination coverage on viral incidence.

Population surveillance in COVID-19 Pandemic is crucial to follow up the pace of disease and its related immunological status. Here we present a cross-sectional study done in Maricá, a seaside town close to the city of Rio de Janeiro, Brazil. Three rounds of study sampling, enrolling a total of 1134 subjects, were performed during May to August 2021. Here we show that the number of individuals carrying detectable IgG antibodies and the neutralizing antibody (NAb) levels were greater in vaccinated groups compared to unvaccinated ones, highlighting the importance of vaccination to attain noticeable levels of populational immunity against SARS-CoV-2. Moreover, we found a decreased incidence of COVID-19 throughout the study, clearly correlated with the level of vaccinated individuals as well as the proportion of individuals with detectable levels of IgG anti-SARS-CoV-2 and NAb. The observed drop occurred even during the introduction of the Delta variant in Maricá, what suggests that the vaccination slowed down the widespread transmission of this variant. Overall, our data clearly support the use of vaccines to drop the incidence associated to SARS-CoV-2.

Use of selective quenching of a photoluminescent probe based on a Eu(III) ß-diketonate complex for determination of methylmercury in produced water after liquid-liquid extraction.

An Eu(III) ß-diketonate complex was produced and employed as a photoluminescent probe to determine methylmercury (CH3Hg+). To establish its molecular structure, the Eu(III) complex was characterized by elemental (CHNS) and thermogravimetric analyses and infrared spectroscopy. After establishing robust conditions to use the Eu(III) complex as an analytical probe, it was employed for the analysis of produced water (PW) samples with the analytical response based on the luminescence suppression proportional to the concentration of CH3Hg+ (a linear model after normalization of the response within the concentration range from 0.2 µg L-1 up to 2.0 µg L-1). Selectivity was guaranteed by a simple liquid-liquid extraction of the analyte in dichloromethane, which also allowed a 50 times pre-concentration factor. The instrumental limit of quantification of 0.2 µg L-1 is equal to the limit established in Brazilian resolution for total mercury content in waters, but pre-concentration (50 times factor) improved the overall method limit of quantification down to 4 ng L-1. Recovery results agreed with the ones achieved using cold vapor atomic absorption spectrometry.

Phenolic Composition, Toxicity Potential, and Antimicrobial Activity of Licania rigida Benth (Chrysobalanaceae) Leaf Extracts.

This study was conducted to evaluate the phenolic composition, toxicity, and antimicrobial activity of Licania rigida Benth, an underexploited wild Licania species. L. rigida leaf fractions (ethyl alcohol and ethyl acetate) were analyzed for their phenolic compound and flavonoid total, and high-performance liquid chromatography/ultraviolet spectra chromatographic profiles. Regarding the extract biological effects, toxicity was measured by acute oral toxicity in Wistar rats, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] method, and apoptosis indicators with DAPI in VERO cells, whereas well-agar diffusion and broth microdilution assays were applied to evaluate the antimicrobial ability. The phytochemical analysis resulted in significant amounts of phenolic compounds and total flavonoids in the extract and fraction, with flavonol-3-O-glycosylates as the main constituent. Regarding the extract and fraction antimicrobial activity, the results showed a significant effect against gram-positive bacteria and fungi, among which Staphylococcus epidermidis and Candida krusei displayed more susceptibility. No toxicity effects were observed in animals. Concerning the cytotoxicity assay, only the highest dose tested exhibited a minimal toxic effect on the analyzed cell lines. These results are relevant considering the increase of multiresistant microorganisms to conventional treatments applied. Therefore, investigating the pharmacological properties of the genus Licania is promising in the search for new sources of antimicrobial compounds.

Licania rigida leaf extract: Protective effect on oxidative stress, associated with cytotoxic, mutagenic and preclinical aspects.

Brazilian plant biodiversity is a rich alternative source of bioactive compounds since plant-derived extracts and/or their secondary metabolites exhibit potential properties to treat several diseases. In this context, Licania rigida Benth (Chrysobalanaceae Family), a large evergreen tree distributed in Brazilian semi-arid regions, deserves attention for its widespread use in popular medicine, although its biological properties are still poorly studied. The aim of this study was to examine (1) acute and sub-chronic oral toxicity at 2000 mg/kg dose; (2) in vitro cytotoxicity at 0.1; 1; 10; 100 or 1000 µg/ml; (3) in vivo mutagenicity at 5, 10 or 20 mg/ml, and (4) potential antioxidant protective effect of L. rigida aqueous leaf extract of (AELr). No marked apparent toxic and genotoxic effects were observed using in vitro and in vivo assays after in vitro treatment of Chinese hamster ovary cell line (CHO-K1) with AELr or in vivo exposure of Wistar rats and Drosophila melanogaster to different extract concentrations. Concerning the antioxidant effect, the extract exhibited a protective effect by decreasing lipid peroxidation as determined by malondialdehyde levels. No significant changes were observed for glutathione (GSH) levels and activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Data demonstrate the beneficial potential of AELr to be employed for therapeutic purposes. However, further studies are required to validate the pharmacological application of this plant extract to develop as a phytotherapeutic formulation.

Polymorphisms at CYP enzymes, NR1I2 and NR1I3 in association with virologic response to antiretroviral therapy in Brazilian HIV-positive individuals.

Virologic failure of antiretroviral therapy (ART) may be explained by single nucleotide polymorphisms (SNPs) in drug absorption and metabolism genes. Here, we characterized the associations between polymorphisms in cytochrome P450 enzymes' genes CYP2B6 and CYP3A4/A5, nuclear receptor genes NR1I2/3, and initial ART efficacy among 203 HIV-positive individuals from Rio de Janeiro. Association between SNPs and virologic control was evaluated after 6 and 12 months of follow-up using Cox regression models. The SNP rs2307424 (NR1I3) was associated with increased virologic response after 12 months of treatment, while rs1523127 (NR1I2), rs3003596, and rs2502815 (NR1I3) were associated with decreased response. Increased virologic response after 12 months (adjHR = 1.54; p = 0.02) was also observed among carriers of the NR1I3 haplotype rs2502815G-rs3003596A-rs2307424A versus the reference haplotype G-A-G. Our results suggest that NR1I2 and NR1I3 variants are associated with virologic responses to ART among Brazilians.

Development and validation of a simple and rapid way to generate low volume of plasma to be used in point-of-care HIV virus load technologies

ABSTRACT A new point-of-care HIV viral load, mPIMA HIV-1/2 VL, Abbott, USA, has been recently developed. This point-of-care viral load requires no skilled person to run and uses a small plasma volume (50 µL). However, obtaining 50 µL of plasma can be a challenge in limited resource settings. We validated a simple and easy method to obtain enough amount of plasma to run a point-of-care viral load. The study utilized 149 specimens from patients failing antiretroviral therapy. At least 250 µL of whole blood was collected in a microtube/EDTA from fingerstick (fs-plasma) and immediately centrifuged. Parallel collection of venous blood to obtain plasma (vp-plasma) was used to compare performance in a point-of-care viral load assay and in methodology used in centralized laboratories Abbott M2000, Abbott, USA. The procedure for plasma collection takes less than 10 min and in 94% of the cases only one fingerstick was sufficient to collect at least 250 µL of blood. The Pearson correlation coefficient value for vp-plasma versus fs-plasma ran on mPIMA was 0.990. The Bland-Altman mean difference (md) for this comparison were virtually zero (md = −0.001) with limits of agreement between −0.225 and 0.223. In addition, the Pearson correlation coefficient value for fs-plasma in mPIMA versus vp-plasma in Abbott M2000 was 0.948 for values above the mPIMA limit of quantification (LoQ; from 800 to 1,000,000 copies/mL). These results validate this simple plasma isolation method capable to be implemented in low resource countries where point-of-care decentralization is deeply needed.

The performance of a new point-of-care HIV virus load technology to identify patients failing antiretroviral treatment.

BACKGROUND: A new point-of-care (POC) HIV virus load technology has been recently developed and designed to be utilized in decentralized settings. Alere Technologies GmbH*, Germany, developed the mPIMA HIV-1/2 VL plasma test which uses real time PCR technology with 50 µl and a turnaround time of one hour. OBJECTIVE: Analyze the performance of mPIMA to detect and quantify HIV-1 and HIV-2 and compare with Abbott M2000 assay fooling patients HIV-1 failing ARV therapy. STUDY DESIGN: In this study we evaluate the mPIMA HIV-1/2 VL plasma test using 413 specimens from 270 patients failing ARV therapy, and compared its performance with Abbott RealTime HIV-1 Viral Load assay on the m2000 system. In addition, were determined VL in plasma specimens obtained from HIV-2 infected patients. RESULTS: The results strongly indicate that mPIMA HIV-1/2 VL plasma test can determine HIV-1 with concordance of 88.9 % (95 % CI 85.4-91.7) the reference test when 1000 HIV-1 VL threshold was used as WHO cutoff to identify therapy failure. The overall correlation between HIV-1 VL was 0928 (Pearson correlation coefficient of Linear regression) and the Bland-Altman showed a mean difference of -0.20 Log cp/mL between the two technology. mPIMA HIV-1/2 VL plasma test was also able to measure HIV-2 viral load in 16 specimens from Guinea-Bissau HIV-1/HIV-2 positive samples. CONCLUSIONS: These data support the use of mPIMA HIV-1/2 VL plasma test to follow up patients and select patients failing ART, guiding immediate clinical decisions such as adherence counseling or ART regimen switch during the patient consultation.

Development and validation of a simple and rapid way to generate low volume of plasma to be used in point-of-care HIV virus load technologies.

A new point-of-care HIV viral load, mPIMA HIV-1/2 VL, Abbott, USA, has been recently developed. This point-of-care viral load requires no skilled person to run and uses a small plasma volume (50µL). However, obtaining 50µL of plasma can be a challenge in limited resource settings. We validated a simple and easy method to obtain enough amount of plasma to run a point-of-care viral load. The study utilized 149 specimens from patients failing antiretroviral therapy. At least 250µL of whole blood was collected in a microtube/EDTA from fingerstick (fs-plasma) and immediately centrifuged. Parallel collection of venous blood to obtain plasma (vp-plasma) was used to compare performance in a point-of-care viral load assay and in methodology used in centralized laboratories Abbott M2000, Abbott, USA. The procedure for plasma collection takes less than 10min and in 94% of the cases only one fingerstick was sufficient to collect at least 250µL of blood. The Pearson correlation coefficient value for vp-plasma versus fs-plasma ran on mPIMA was 0.990. The Bland-Altman mean difference (md) for this comparison were virtually zero (md=-0.001) with limits of agreement between -0.225 and 0.223. In addition, the Pearson correlation coefficient value for fs-plasma in mPIMA versus vp-plasma in Abbott M2000 was 0.948 for values above the mPIMA limit of quantification (LoQ; from 800 to 1,000,000copies/mL). These results validate this simple plasma isolation method capable to be implemented in low resource countries where point-of-care decentralization is deeply needed.

Antiretroviral therapy-induced paradoxical worsening of previously healed Mycobacterium haemophilum cutaneous lesions in advanced HIV infection.

Mycobacterium haemophilum is a nontuberculous mycobacterium that causes localized or disseminated disease, mainly in immunocompromised hosts. We report the case of a 35-year-old HIV-infected woman who presented with several enlarging cutaneous lesions over the arms and legs. Histopathological examination revealed the diagnosis of a cutaneous mycobacterial disease. Mycobacterial analyses unveiled M. haemophilum infection. Six months after completion of a successful antimycobacterial treatment, she developed an immune reconstitution inflammatory syndrome (IRIS). This paradoxical relapse presented as tenderness, redness and swelling at the precise sites of the healed lesions and took place in the setting of significant recovery of the CD4 cell count (from 05 to 318 cells/mm 3 ). Microbiological analyses of these worsening lesions were negative, and they spontaneously remitted without the initiation of a novel antimycobacterial treatment cycle. M. haemophilum infection should always be considered as a cause of skin lesions in immunocompromised subjects. Physicians should be aware of the possibility of IRIS as a complication of successful antiretroviral therapy in HIV-infected patients with M. haemophilum infection.

Palate ulcer, uvular destruction and nasal septal perforation caused by Sporothrix brasiliensis in an HIV-infected patient.

Sporotrichosis is a human and animal disease caused by dimorphic pathogenic species of the genus Sporothrix. We report a dramatic presentation of Sporothrix brasiliensis infection, with destruction of the nasal septum, soft palate, and uvula of an HIV-infected woman. She was successfully treated with amphotericin B deoxycholate followed by itraconazole. Sporotrichosis remains a neglected opportunistic infection in patients with AIDS and awareness of this potentially fatal infection is of utmost importance.

Chlamydia trachomatis asymptomatic urethritis recurrence among males living with HIV-1.

A prevalence of 3.47% of asymptomatic Chlamydia trachomatis urethritis has been previously reported among males living with HIV infection in Brazil. This study aims to assess the recurrence of C. trachomatis urethritis three years later in the same cohort of patients and analyze associated risk factors. A total of 115 male patients diagnosed with HIV infection, with no symptoms of urethritis and observed since May of 2015 in followup visits were enrolled. They had urine samplers tested by PCR for C. trachomatis and N. gonorrhoeae between February and March 2018. Results: Three of the four patients who had asymptomatic C. trachomatis urethritis three years before were recurrently positive for C. trachomatis urethritis. Two new patients were diagnosed as positives, accounting for a total asymptomatic C. trachomatis urethritis prevalence of 4.34%. The prevalence during the whole study was 5.21%. The relative risk for a new urethritis episode among those previously diagnosed with urethritis is RR=41.62 (95% CI: 9.42-183.84), p < 0.01. Patients who presented asymptomatic urethritis anytime and who were recurrently positive for C. trachomatis had a lower mean age (p<0.01). Married individuals were protected regarding asymptomatic urethritis [p<0.01, OR = 0.04 (0.005-0.4)] and had lower risk to develop recurrence [p<0.01, RR = 0.86 (0.74-0.99)]. Illicit drugs users had risk associated to asymptomatic urethritis [p=0.02, OR= 5.9 (1.03-34)] and higher risk to develop recurrence [p<0.01, RR=1.1 (1-1.22)]. Conclusion: The recurrence of asymptomatic C. trachomatis urethritis after treatment among males living with HIV infection in Brazil can be considered high and should not be neglected.

Gastrointestinal CMV Disease and Tuberculosis in an AIDS Patient: Synergistic Interaction between Opportunistic Coinfections.

The AIDS pandemic has made diseases such as tuberculosis, CMV disease, and other opportunistic infections more prevalent; these diseases may even be found to be associated among themselves, and the natural history of each disease may present in an unusual manner. We report the case of a 41-year-old man with HIV (CD4 of 144 cells/dL) and HCV with hematochezia due to tuberculosis in the ileocecal valve and descending colon and CMV tissue invasive disease in the esophagus and descending colon. Coinfection among tuberculosis and cytomegalovirus in the gastrointestinal tract was described only once in a patient with a recent diagnosis of HIV that affected the distal ileum and ascending colon. We will discuss the peculiarities of the case and the behavior of the immune system in the face of simultaneous opportunistic infections. This is a challenging scenario that has scarce publications and is of great clinical importance.

Drug metabolism and transport gene polymorphisms and efavirenz adverse effects in Brazilian HIV-positive individuals.

Objectives: There are limited data regarding efavirenz pharmacogenetics in admixed populations. The Brazilian population is highly admixed. In a Brazilian cohort, we sought to characterize associations between efavirenz adverse effects (all-cause and CNS) and polymorphisms in seven genes known or suspected to affect efavirenz metabolism and transport. Methods: We studied 225 HIV-positive individuals who had been prescribed efavirenz-containing regimens at a hospital in Rio de Janeiro, Brazil. Eighty-nine cases had efavirenz adverse effects, including 43 with CNS adverse effects, while 136 controls had no adverse effect of any antiretroviral after treatment for at least 6 months. A total of 67 candidate polymorphisms in ABCB1, CYP2A6, CYP2B6, CYP3A4, CYP3A5, NR1I2 and NR1I3 genes were selected for association analysis. Admixture was assessed using 28 ancestry-informative polymorphisms previously validated for the Brazilian population. Associations were evaluated with logistic regression models adjusted for sex and genetic ancestry. Results: There was extensive African, European and Native American admixture in the cohort. Increased all-cause adverse effects were associated with the CYP2B6 genotype combination 15582CC-516TT-983TT (OR = 7.26, P = 0.003) and with the CYP2B6 slow metabolizer group 516TT or 516GT-983CT (OR = 3.10, P = 0.04). CNS adverse effects were nominally associated with CYP3A4 rs4646437 (OR = 4.63, P = 0.014), but not after adjusting for multiple comparisons. Conclusions: In a highly admixed Brazilian cohort, the CYP2B6 slow metabolizer genotype was associated with an increased risk of efavirenz adverse effects.

A malar rash from inner Rio de Janeiro State, Brazil.

A 49-year-old previously healthy woman from Rio de Janeiro State, Brazil, presented with a right malar rash that started as a tiny pustule and progressed to an ulcerated papulonodular lesion within ten weeks. A presumptive diagnosis of zoonotic sporotrichosis was made based on excellent response to treatment and epidemiological linkage with a diseased cat.

Prevalence of asymptomatic urethritis by Chlamydia trachomatis and Neisseria gonorrhoeae and associated risk factors among males living with HIV-1.

OBJECTIVES: The increase in HIV transmissibility in non-ulcerative sexually transmitted infection is already well-established. It is estimated that symptomatic carriers of N. gonorrhoeae and C. trachomatis have a relative risk of 4.8-fold and 3.6-fold, respectively, for the sexual acquisition of HIV. This type of evaluation for asymptomatic urethritis is necessary to reinforce strategies to combat HIV transmission. This study aims to assess the prevalence of patients with asymptomatic urethritis among men diagnosed with HIV-1 and determine the risk factors associated with this infection. METHODS: We enrolled a total of 115 male patients aged 18 years or older who have been diagnosed with HIV infection and have no symptoms of urethritis or other sexually transmitted infections and who have been evaluated between May and August 2015 in a follow-up visit at the Immunology Outpatient Clinic of a Brazilian University Hospital. RESULTS: Four asymptomatic patients were positive for C. trachomatis and were considered asymptomatic carriers of urethritis. Prevalence was 3.47%. Patients who were positive for C. trachomatis urethritis had a lower mean age (p = 0.015). CONCLUSION: The presence of asymptomatic sexually transmitted infection is a challenge in clinical practice. We recommend that, in outpatient practice, the habit of inquiring on previous sexual behavior to obtain more information about risks and associations with asymptomatic sexually transmitted infection, a routine physical examination and complementary tests to detect STI pathogens should be performed to discard these conditions. The development of rapid tests for this purpose should also be encouraged.