Adolescent experiences during perinatal care in the COVID-19 pandemic: synthesis of qualitative studies.

OBJECTIVES: To understand how the perinatal care experiences among adolescents were impacted during the early years of the COVID-19 pandemic. STUDY DESIGN: Integrative review. METHODS: We performed a search in the literature focusing on qualitative studies regarding the perceptions of pregnant adolescents during the pandemic (2020-2023). We described the most frequent thematic axes observed in the included studies, and we synthesized the results. RESULTS: The selection involved 69 articles, resulting in 9 studies from 7 countries (Indonesia, Kenya, the United Kingdom, South Africa, the United States, Malawi, and India). The studies highlight six main thematic axes: 1. Economic impact: the pandemic adversely influenced personal and family conditions, leading to early marriages and violence and exacerbating pre-existing economic inequalities. 2. Mental health: increased anxiety, depression, isolation, and fear among pregnant adolescents, with a focus on concerns related to contamination and perinatal uncertainties. 3. Compromised perinatal care: restrictions during prenatal and delivery care and lack of emotional and professional support lead to negative impacts on care for pregnant adolescents. 4. Breakdown of family Support network: school closures, family losses, and increased domestic violence affected family dynamics, influencing the occurrence of early pregnancies. 5. Impact on sexual education: school closures hindered access to contraceptives, contributing to unplanned pregnancies. 6. Vaccine hesitancy: misinformation led to hesitancy among pregnant women, highlighting the need for better communication to increase confidence in vaccination. CONCLUSIONS: The review emphasizes the wide geographic variety of the studies and highlights the interconnection between economic, social, and mental health factors. The pandemic intensified preexisting challenges, underscoring the importance of comprehensive support for pregnant adolescents, including emotional and psychological support. The COVID-19 pandemic exacerbated social and economic inequalities, negatively impacting the perinatal experiences of pregnant adolescents. The emphasis is on the need for comprehensive support, considering psychosocial factors, highlights the importance of more inclusive and sensitive health policies addressing the specific needs of this group during public health crises. The identified thematic axes, spanning economic, mental health, perinatal care, family support networks, sexual education, and vaccine hesitancy, illuminate the intricate challenges faced by adolescents during the pandemic. The identification of these axes provided a comprehensive analysis of the diverse consequences experienced by adolescents during the COVID-19 pandemic. It also allows the proposition of tailored interventions to mitigate the adverse effects on adolescent well-being and inform public health strategies for future pandemics or crises.

Specific characteristics of urethral strictures in a developing country (Brazil).

PURPOSE: Evaluate the main etiologies and clinical characteristics of male urethral stricture disease (USD) in Brazil. METHODS: This multicentric study was performed using retrospective data collected from six Brazilian referral centers of urethral reconstruction. The database comprised data from 899 patients with USD who had undergone surgical treatment from 2008 to 2018. Age, stricture site and primary stricture etiology were identified for each patient. RESULTS: The mean age was 52.13 ± 16.9 years. The most common etiology was iatrogenic (43.4%), followed by idiopathic (21.7%), trauma (21.5%) and inflammatory (13.7%). Of the iatrogenic causes, 59% were secondary to urethral instrumentation (60% by urethral catheterization and 40% by transurethral procedures), 24.8% by other procedures (prostatectomy, radiotherapy, postectomy) and 16.2% by failed hypospadia repairs. Pelvic fracture urethral distraction injuries were responsible for most of the trauma-related strictures (62.7%). When stratified by age, the most common stricture etiology was trauma in the 0-39 years old group (42.8%), idiopathic in the 40-59 years old group (32.4%) and iatrogenic in patients over 60 years old (68%). In regard to the stricture site, 80% presented with an anterior urethral stricture and 20% with a posterior stenosis. In the anterior stenosis group, the most common stricture site was bulbar (39.5%). CONCLUSION: In Brazil, as in many developed countries, the most common cause of urethral stricture diseases is iatrogenic, especially urethral catheterization. These findings emphasize the need of a careful urethral manipulation and a better training of healthcare professionals. Trauma is still responsible for a great proportion of strictures and inflammatory etiologies are now less frequently observed.

Behavioral aspects of Lutzomyia longipalpis (Diptera: Psychodidae) in urban area endemic for visceral leishmaniasis.

The study of some of the behavioral aspects of the main vector of Leishmania infantum chagasi Cunha & Chagas in the Americas, Lutzomyia longipalpis (Lutz & Neiva), such as dispersion, population size, and vector survival rates, is important for the elucidation of the mechanisms of visceral leishmaniasis transmission. These parameters were studied by means of capture-mark-release-recapture experiments in an urban area of Campo Grande municipality, an endemic area of visceral leishmaniasis, situated in Mato Grosso do Sul state, Brazil. Six capture-mark-release-recapture experiments were undertaken between November 2009 and November 2010 and once in January 2012 with a view to assessing the population size and survival rate of Lu. longipalpis. The insects were released in a peridomicile surrounded by 13 residences. The recaptures were undertaken with automatic light traps for four consecutive weeks after release in the surrounding area. In total, 3,354 sand flies were captured, marked, and released. The overall recapture rate during the capture-mark-release-recapture experiments was 4.23%, of which 92.45% were recaptured at the release site, indicating limited dispersal. The greatest distance recorded from the release site was 165 m for males and 241 m for females. The male daily survival rate, calculated on the basis of regressions from the numbers of marked recaptured insects during the 15 successive days after release was 0.897. The estimated male population size measured by the Lincoln Index was 10,947.127. Though Lu. longipalpis presented a limited dispersion the physical barriers typical of urban environments did not prevent the sand flies from flying long distances.

Intravaginal artificial insemination in bitches using frozen/thawed semen after dilution in powdered coconut water (ACP-106c).

The aim of this study was to evaluate powdered coconut water extender (ACP-106c; ACP Serviços Tecnológicos Ltda, ACP Biotecnologia, Fortaleza, Ceará, Brazil) as a diluent for freezing dog semen and the fertility after vaginal insemination of semen frozen therein. Ten ejaculates were collected from five dogs, evaluated fresh, diluted in ACP-106c, 10% egg yolk and 6% glycerol, cooled and frozen. In the first phase of the study, straws with frozen semen were thawed and immediately subjected to the same analysis as the fresh semen and, in addition, to Computer-Assisted Semen Analysis (CASA). In phase 2, 10 bitches that had been subjected to natural breeding during a preceding oestrous cycle were vaginally inseminated with thawed semen that had been re-diluted in ACP-106c. After thawing, a mean of 77% sperm motility was obtained through subjective analysis and 77.3% through CASA. Following artificial insemination, a 60% pregnancy rate was observed, resulting in a 50% parturition rate and a mean litter size of 3.4 (SEM 0.6), with 47.1% males and 52.9% females. ACP-106c can be successfully used for freezing canine semen, and vaginal deposition of such semen yields similar pregnancy rates to those reported in other studies.

Occurrence of white rust (Albugo ipomoeae-panduratae) on Ipomoea acuminate In the brazilian mid-west.

Spontaneous plants of Ipomoea acuminata ("morning glory") exhibiting white rust pustules were found in a field crop area of Planaltina, DF, in the fall season of 2010 and the disease causal agent was identified as Albugo ipomoea-panduratae (Oomycota). No reports of the association between A. ipomoea-panduratae and I. acuminata were known in Brazil previously to 2010. A reference specimen was deposited at the University of Brasilia Mycological Reference Collection.

Molecular and morphological diversity, qualitative chemical profile and antioxidant activity of filamentous fungi of the digestive tract of Phylloicus sp. (Trichoptera: Calamoceratidae).

This study aimed to identify by molecular analysis, morphology, chemistry and antioxidant extracts of filamentous fungi isolated from the digestive tract of Phylloicus sp, an aquatic insect that lives on leaf packages in tropical streams and participates together with fungi of the decomposition of plant substrates in aquatic habitats. Insect larvae of Phylloicus sp. were collected in streams in the state of Tocantins, Brazil. Fungi were isolated from the digestive tract of larvae after disinfection and dissection, then described and purified for identification purposes and testing for antioxidant activity. Molecular identity was performed of ITS1 and ITS4, TUB e TEF sequencing. Fungal extracts were produced in 70% ethanol solution and later lyophilized. For analysis of chemical groups of extracts, thin layer chromatography (TLC) was performed in two mobile phases and different developers. Morphology was performed by optical microscopy stained with Toluidine Blue and measurement performed using the ImageJ program. Antioxidant activity performed in TLC and by quantitative method for DPPH and hydrogen peroxide (H2O2) radicals. Four fungi were identified: Endomelanconiopsis endophytica, Myxospora musae, Neopestalotiopsis cubana and Fusarium pseudocircinatum. The TLC showed several spots with acetone/chloroform mobile phase and UV 254 nm developers and I2 vapor. Fungal extracts demonstrate antioxidant action to reduce the DPPH free radical and especially for H2O2 above 50%, E. endophytica 91.6%, M. musae 87.8%, N. cubana 89.5% and 92.3% for F. pseudocircinatum. This study demonstrated that the molecular technique by PCR was satisfactory for identifying fungi, and extracts with numerous chemical groups and potent reducing agents. Thus future work, should be carried out evaluating these four species for industrial use.

Phytochemical characterization, and antioxidant and antibacterial activities of the hydroethanolic extract of Anadenanthera peregrina stem bark.

The Brazilian Cerrado biome consists of a great variety of endemic species with several bioactive compounds, and Anadenanthera peregrina (L.) Speg is a promising species. In this study, we aimed to perform phytochemical characterization and evaluate the antioxidant and antibacterial activities against Staphylococcus aureus and Escherichia coli of the hydroethanolic extract of A. peregrina stem bark. The barks were collected in the Botanical Garden of Goiânia, Brazil. The hydroethanolic extract was obtained by percolation and subjected to physicochemical screening, total phenolic content estimation, high-performance liquid chromatography (HPLC) fingerprinting, and antioxidant (IC50 values were calculated for the 2,2-diphenyl-1-picrylhydrazyl assay - DPPH) and antibacterial activity determination. The pH of the extract was 5.21 and density was 0.956 g/cm3. The phytochemical screening indicated the presence of cardiac glycosides, organic acids, reducing sugars, hemolytic saponins, phenols, coumarins, condensed tannins, flavonoids, catechins, depsides, and depsidones derived from benzoquinones. The extract showed intense hemolytic activity. The total phenolic content was 6.40 g GAE 100 g-1. The HPLC fingerprinting analysis revealed the presence of gallic acid, catechin, and epicatechin. We confirmed the antioxidant activity of the extract. Furthermore, the extract did not inhibit the growth of E. coli colonies at any volume tested, but there were halos around S. aureus colonies at all three volumes tested. These results contribute to a better understanding of the chemical composition of A. peregrina stem bark and further support the medicinal applications of this species.

Use of two anesthetic combinations for semen collection by electroejaculation from captive coatis (Nasua nasua).

The objective was to compare the effects of ketamine-xylazine or tiletamine-zolazepam combinations as anesthetic protocols for captive coatis (Nasua nasua) for semen collection by electroejaculation. Five mature male coatis were physically restrained and then anesthetized by im injections of ketamine (10mg/kg) plus xylazine (1mg/kg) or a tiletamine-zolazepam combination (8 mg/kg). For the two combinations, additional quarter-doses of ketamine or the tiletamine-zolazepam combination were administered when necessary. Semen was collected by electroejaculation and immediately evaluated for color, volume, pH, sperm motility, vigor, morphology, acrosomal integrity, and percentage of live cells. Overall, collection of nine ejaculates was attempted from five animals for each treatment. Regardless of the anesthetic combination, all animals developed an erection during each attempt to collect semen. Ejaculates were obtained in all (9 of 9) attempts that used ketamine-xylazine for anesthesia, but in only 3 of 9 attempts (P<0.05) when tiletamine-zolazepam was used. All ejaculates contained sperm, with no significant differences in semen characteristics between the two anesthetic combinations. Recovery was smooth in all animals. In conclusion, semen collection by electroejaculation in coatis was significantly more successful with the use of a ketamine-xylazine combination than with tiletamine-zolazepam.

Obesity and hypertension in Latin America: Current perspectives.

In the countries of Central America, South America and the Caribbean, there has been a dramatic rise in obesity, the metabolic syndrome, hypertension and other cardiovascular risk factors in the last few decades. Epidemiological evidence highlights a consistent correlation between obesity and hypertension, and the presence of obesity predisposes an individual to a greater risk of hypertension although the mechanisms remain unclear. Obesity and hypertension are two key drivers of the cardio-renal disease continuum, and patients with uncontrolled cardiovascular risk in their mid-life will likely have an increased risk of clinical cardiovascular and renal outcomes in old age. This article summarizes the current status for the prevalence and consequences of obesity and hypertension in Latin America, with the aim of initiating a call to action to all stakeholders for greater implementation of primary prevention strategies, particularly in the young.

Dependent component analysis for the magnetogastrographic detection of human electrical response activity.

The detection of the basic electric rhythm (BER), composed of a 3 cycles min(-1) oscillation, can be performed using SQUID magnetometers. However, the electric response activity (ERA), which is generated when the stomach is performing a mechanical activity, was detected mainly by invasive electrical measurements and only recently was one report published describing its detection by magnetic measurements. This study was performed with the aim of detecting the ERA noninvasively after a meal. MGG recordings were made with a 74-channel first-order gradiometer (Magnes II, biomagnetic technologies) housed in a shielded room. Seven nonsymptomatic volunteers were measured in the study. Initially a 10 min recording was performed with the subject in the fasted state. A 250 kcal meal was given to the subject without moving out of the magnetometers and two epochs of 10 min each were acquired. The signals were processed to remove cardiac interference by an algorithm based on a variation of independent component analysis (ICA), then autoregressive and wavelet analysis was performed. Preliminary results have shown that there is an increase in the signal power at higher frequencies around (0.6 Hz-1.3 Hz) usually associated with the basic electric rhythm. The center of the frequency band and its width varied from subject to subject, demonstrating the importance of pre-prandial acquisition as a control. Another interesting finding was an increase in power after about 5 min of meal ingestion. This period roughly agrees with the lag phase of gastric emptying, measured by scintigraphy and other techniques. We confirm that MGG can detect the electric response activity in normal volunteers. Further improvements in signal processing and standardization of signal acquisition are necessary to ascertain its possible use in clinical situations.

Nycthemeral Rhythm of Phlebotominae (Diptera: Psychodidae) in a Craggy Region, Transitioning Between the Wetland and the Plateau, Brazil.

Recording the nycthemeral rhythm of sand flies allows the evaluation of the daily activity in different ecotypes, the period of greatest activity, and their degree of anthropophily. We investigated the fauna and the rhythm of sand fly activity in an ecotourism region in Mato Grosso do Sul (MS) state, Brazil. Sand flies were captured monthly, using a Shannon trap for 24 h periods between July 2012 and June 2014. We collected 1,815 sand flies, in which Lutzomyia whitmani (=Nyssomyia whitmani, sensu Galati) and Lutzomyia longipalpis were the most abundant species during the dry season, with activity from 5 p.m.-7 a.m. and 6 p.m.-5 a.m., respectively. Both species require particular attention as vectors of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum in several regions of Brazil, including MS. However, Lutzomyia dispar was more anthropophilic, and was most active between January and March, from 5 p.m. to 5 a.m. Lutzomyia misionensis (=Pintomyia misionensis, sensu Galati) was present throughout both years, active from 4 p.m. to 5 a.m. Other species were active from 5 p.m. to 6 a.m. Due to intense tourism in the months that coincide with a high number of vectors for leishmaniases in Piraputanga, it is essential to determine vector-monitoring strategies in the area by investigating sand fly rhythm while not neglecting other periods of the year when the insects are present.

Hypolipidemic activity of P-methoxycinnamic diester (PCO-C) isolated from Copernicia prunífera against Triton WR-1339 and hyperlipidemic diet in mice.

Carnauba wax is extracted from the leaves of the Copernicia prunífera and contains approximately 80% of esters in its composition. The purpose of the present study was evaluate the hypolipidemic effect of p-methoxycinnamic diesters (PCO-C) extracted from Copernicia prunífera in a model of acute and chronic dyslipidemia in mice. The levels of total cholesterol and triglycerides were significantly reduced plasma levels in PCO-C at the dose of 100mg/kg in a model of acute and chronic dyslipidemia. Histological studies showed that PCO-C has no hepatotoxic effect and reduces hepatic steatosis in animals that consumed hyperlipidemic ration. Thus, it was concluded that PCO-C isolated from Copernicia Prunifera was effective in reducing total cholesterol and triglyceride levels in both dyslipidemia induction models. The finding indicates that PCO-C might be beneficial in treatment of hyperlipidemia and atherosclerosis.

Phytochemical characterization, and antioxidant and antibacterial activities of the hydroethanolic extract of Anadenanthera peregrina stem bark / Caracterização fitoquímica, atividade antioxidante e antibacteriana do extrato hidroetanólico de cascas do caule de Anadenanthera peregrina

The Brazilian Cerrado biome consists of a great variety of endemic species with several bioactive compounds, and Anadenanthera peregrina (L.) Speg is a promising species. In this study, we aimed to perform phytochemical characterization and evaluate the antioxidant and antibacterial activities against Staphylococcus aureus and Escherichia coli of the hydroethanolic extract of A. peregrina stem bark. The barks were collected in the Botanical Garden of Goiânia, Brazil. The hydroethanolic extract was obtained by percolation and subjected to physicochemical screening, total phenolic content estimation, high-performance liquid chromatography (HPLC) fingerprinting, and antioxidant (IC50 values were calculated for the 2,2-diphenyl-1-picrylhydrazyl assay - DPPH) and antibacterial activity determination. The pH of the extract was 5.21 and density was 0.956 g/cm3. The phytochemical screening indicated the presence of cardiac glycosides, organic acids, reducing sugars, hemolytic saponins, phenols, coumarins, condensed tannins, flavonoids, catechins, depsides, and depsidones derived from benzoquinones. The extract showed intense hemolytic activity. The total phenolic content was 6.40 g GAE 100 g-1. The HPLC fingerprinting analysis revealed the presence of gallic acid, catechin, and epicatechin. We confirmed the antioxidant activity of the extract. Furthermore, the extract did not inhibit the growth of E. coli colonies at any volume tested, but there were halos around S. aureus colonies at all three volumes tested. These results contribute to a better understanding of the chemical composition of A. peregrina stem bark and further support the medicinal applications of this species.

O bioma Cerrado brasileiro apresenta em uma grande variedade de espécies endêmicas com diversos compostos bioativos, e Anadenanthera peregrina (L.) Speg é uma espécie promissora. Neste estudo, objetivamos realizar a caracterização fitoquímica e avaliar as atividades antioxidantes e antibacterianas contra Staphylococcus aureus e Escherichia coli do extrato hidroetanólico de cascas do caule de A. peregrina. As cascas foram coletadas no Jardim Botânico de Goiânia, Brasil. O extrato hidroetanólico foi obtido por percolação e submetido a triagem físicoquímica, estimativa de conteúdo fenólico total, impressão digital por cromatografia líquida de alta eficiência (HPLC) e determinação da atividade antioxidante (valores de IC50 foram calculados para o ensaio 2,2-difenil-1-picril-hidrazil) e antibacteriana. O pH do extrato foi de 5,21 e a densidade foi de 0,956 g/cm3. A triagem fitoquímica indicou a presença de glicosídeos cardíacos, ácidos orgânicos, açúcares redutores, saponinas hemolíticas, fenóis, cumarinas, taninos condensados, flavonóides, catequinas, depsídios e depsidonas derivados de benzoquinonas. O extrato mostrou intensa atividade hemolítica. O conteúdo fenólico total foi de 6,40 g de GAE 100 g-1. A análise por impressão digital por HPLC revelou a presença de ácido gálico, catequina e epicatequina. Confirmamos a atividade antioxidante do extrato. Além disso, o extrato não inibiu o crescimento de colônias de E. coli em nenhum volume testado, mas houve halos em torno das colônias de S. aureus nos três volumes testados. Estes resultados contribuem para uma melhor compreensão da composição química da casca de A. peregrina e apoia ainda mais as aplicações medicinais desta espécie.

Phytochemical characterization, and antioxidant and antibacterial activities of the hydroethanolic extract of Anadenanthera peregrina stem bark / Caracterização fitoquímica, atividade antioxidante e antibacteriana do extrato hidroetanólico de cascas do caule de Anadenanthera peregrina

The Brazilian Cerrado biome consists of a great variety of endemic species with several bioactive compounds, and Anadenanthera peregrina (L.) Speg is a promising species. In this study, we aimed to perform phytochemical characterization and evaluate the antioxidant and antibacterial activities against Staphylococcus aureus and Escherichia coli of the hydroethanolic extract of A. peregrina stem bark. The barks were collected in the Botanical Garden of Goiânia, Brazil. The hydroethanolic extract was obtained by percolation and subjected to physicochemical screening, total phenolic content estimation, high-performance liquid chromatography (HPLC) fingerprinting, and antioxidant (IC50 values were calculated for the 2,2-diphenyl-1-picrylhydrazyl assay - DPPH) and antibacterial activity determination. The pH of the extract was 5.21 and density was 0.956 g/cm3. The phytochemical screening indicated the presence of cardiac glycosides, organic acids, reducing sugars, hemolytic saponins, phenols, coumarins, condensed tannins, flavonoids, catechins, depsides, and depsidones derived from benzoquinones. The extract showed intense hemolytic activity. The total phenolic content was 6.40 g GAE 100 g-¹. The HPLC fingerprinting analysis revealed the presence of gallic acid, catechin, and epicatechin. We confirmed the antioxidant activity of the extract. Furthermore, the extract did not inhibit the growth of E. coli colonies at any volume tested, but there were halos around S. aureus colonies at all three volumes tested. These results contribute to a better understanding of the chemical composition of A. peregrina stem bark and further support the medicinal applications of this species.

O bioma Cerrado brasileiro apresenta em uma grande variedade de espécies endêmicas com diversos compostos bioativos, e Anadenanthera peregrina (L.) Speg é uma espécie promissora. Neste estudo, objetivamos realizar a caracterização fitoquímica e avaliar as atividades antioxidantes e antibacterianas contra Staphylococcus aureus e Escherichia coli do extrato hidroetanólico de cascas do caule de A. peregrina. As cascas foram coletadas no Jardim Botânico de Goiânia, Brasil. O extrato hidroetanólico foi obtido por percolação e submetido a triagem físico química, estimativa de conteúdo fenólico total, impressão digital por cromatografia líquida de alta eficiência(HPLC) e determinação da atividade antioxidante (valores de IC50 foram calculados para o ensaio 2,2-difenil-1-picril-hidrazil) e antibacteriana. O pH do extrato foi de 5,21 e a densidade foi de 0,956 g/cm3. A triagem fitoquímica indicou a presença de glicosídeos cardíacos, ácidos orgânicos, açúcares redutores, saponinas hemolíticas, fenóis, cumarinas, taninos condensados, flavonóides, catequinas, depsídios e depsidonas derivados de benzoquinonas. O extrato mostrou intensa atividade hemolítica. O conteúdo fenólico total foi de 6,40 g de GAE 100 g-1. A análise por impressão digital por HPLC revelou a presença de ácido gálico, catequina e epicatequina. Confirmamos a atividade antioxidante do extrato. Além disso, o extrato não inibiu o crescimento de colônias de E. coli em nenhum volume testado, mas houve halos em torno das colônias de S. aureus nos três volumes testados. Estes resultados contribuem para uma melhor compreensão da composição química da casca de A. peregrina e apoia ainda mais as aplicações medicinais desta espécie.

Phytochemical characterization, and antioxidant and antibacterial activities of the hydroethanolic extract of Anadenanthera peregrina stem bark

Abstract The Brazilian Cerrado biome consists of a great variety of endemic species with several bioactive compounds, and Anadenanthera peregrina (L.) Speg is a promising species. In this study, we aimed to perform phytochemical characterization and evaluate the antioxidant and antibacterial activities against Staphylococcus aureus and Escherichia coli of the hydroethanolic extract of A. peregrina stem bark. The barks were collected in the Botanical Garden of Goiânia, Brazil. The hydroethanolic extract was obtained by percolation and subjected to physicochemical screening, total phenolic content estimation, high-performance liquid chromatography (HPLC) fingerprinting, and antioxidant (IC50 values were calculated for the 2,2-diphenyl-1-picrylhydrazyl assay - DPPH) and antibacterial activity determination. The pH of the extract was 5.21 and density was 0.956 g/cm3. The phytochemical screening indicated the presence of cardiac glycosides, organic acids, reducing sugars, hemolytic saponins, phenols, coumarins, condensed tannins, flavonoids, catechins, depsides, and depsidones derived from benzoquinones. The extract showed intense hemolytic activity. The total phenolic content was 6.40 g GAE 100 g-1. The HPLC fingerprinting analysis revealed the presence of gallic acid, catechin, and epicatechin. We confirmed the antioxidant activity of the extract. Furthermore, the extract did not inhibit the growth of E. coli colonies at any volume tested, but there were halos around S. aureus colonies at all three volumes tested. These results contribute to a better understanding of the chemical composition of A. peregrina stem bark and further support the medicinal applications of this species.

Resumo O bioma Cerrado brasileiro apresenta em uma grande variedade de espécies endêmicas com diversos compostos bioativos, e Anadenanthera peregrina (L.) Speg é uma espécie promissora. Neste estudo, objetivamos realizar a caracterização fitoquímica e avaliar as atividades antioxidantes e antibacterianas contra Staphylococcus aureus e Escherichia coli do extrato hidroetanólico de cascas do caule de A. peregrina. As cascas foram coletadas no Jardim Botânico de Goiânia, Brasil. O extrato hidroetanólico foi obtido por percolação e submetido a triagem físico-química, estimativa de conteúdo fenólico total, impressão digital por cromatografia líquida de alta eficiência (HPLC) e determinação da atividade antioxidante (valores de IC50 foram calculados para o ensaio 2,2-difenil-1-picril-hidrazil) e antibacteriana. O pH do extrato foi de 5,21 e a densidade foi de 0,956 g/cm3. A triagem fitoquímica indicou a presença de glicosídeos cardíacos, ácidos orgânicos, açúcares redutores, saponinas hemolíticas, fenóis, cumarinas, taninos condensados, flavonóides, catequinas, depsídios e depsidonas derivados de benzoquinonas. O extrato mostrou intensa atividade hemolítica. O conteúdo fenólico total foi de 6,40 g de GAE 100 g-1. A análise por impressão digital por HPLC revelou a presença de ácido gálico, catequina e epicatequina. Confirmamos a atividade antioxidante do extrato. Além disso, o extrato não inibiu o crescimento de colônias de E. coli em nenhum volume testado, mas houve halos em torno das colônias de S. aureus nos três volumes testados. Estes resultados contribuem para uma melhor compreensão da composição química da casca de A. peregrina e apoia ainda mais as aplicações medicinais desta espécie.

In vivo formation of single-strand breaks in DNA by hydrogen peroxide is mediated by the Haber-Weiss reaction.

Phenanthroline and bipyridine, strong chelators of iron, protect DNA from single-strand break formation by H2O2 in human fibroblasts. This fact strongly supports the concept that these DNA single-strand breaks are produced by hydroxyl radicals generated by a Fenton-like reaction between intracellular Fe2+ and H2O2: H2O2 + Fe2+----Fe3+ + OH- + OH: Corroborating this idea is the fact that thiourea, an effective OH radical scavenger, prevents the formation of DNA single-strand breaks by H2O2 in nuclei from human fibroblasts. The copper chelator diethyldithiocarbamate, a strong inhibitor of superoxide dismutase, greatly enhances the in vivo production of DNA single-strand breaks by H2O in fibroblasts. This supports the idea that Fe3+ is reduced to Fe2+ by superoxide ion: O divided by 2 + Fe3+----O2 + Fe2+; and therefore that the sum of this reaction and the Fenton reaction, namely the so-called Haber-Weiss reaction, H2O2 + O divided by 2----O2 + OH- + OH; represents the mode whereby OH radical is produced from H2O2 in the cell. EDTA completely protects DNA from single-strand break formation in nuclei. The chelator therefore removes iron from the chromatin, and although the Fe-EDTA complex formed is capable of reacting with H2O2, the OH radical generated under these conditions is not close enough to hit DNA. Therefore iron complexed to chromatin functions as catalyst for the Haber-Weiss reaction in vivo, similarly to the role played by Fe-chelates in vitro.

Protection of mammalian cells by o-phenanthroline from lethal and DNA-damaging effects produced by active oxygen species.

Active oxygen species are suspected as being a cause of the cellular damage that occurs at the site of inflammation. Phagocytic cells accumulate at these sites and produce superoxide ion, hydrogen peroxide and hydroxyl radical. The ultimate killing species, the cellular target and the mechanism whereby the lethal injury is produced are unknown. We exposed mouse fibroblasts to xanthine oxidase and acetaldehyde, a system which mimics the membrane of phagocytic cells in terms of production of oxygen species. We observed that the generation of these species produced DNA strand breaks and cellular death. The metal chelator o-phenanthroline completely abolished the former effect, and at the same time it effectively protected the cells from lethal injuries. Because complexing iron o-phenanthroline prevents the formation of hydroxyl radical by the Fendon reaction (Fe(II) + H2O2----Fe(III) + OH- + OH.), it is proposed that most of the cell death and DNA damage are brought about by OH radical, produced from other species by iron-mediated reactions.

Correlation between cytotoxic effect of hydrogen peroxide and the yield of DNA strand breaks in cells of different species.

The rate of loss of reproductive capacity produced by hydrogen peroxide was shown to be 6-times faster for human fibroblasts than for Chinese hamster fibroblasts. Mouse fibroblasts exhibited an intermediate response. The explanation for that does not lie in the different capacities of these cells to destroy H2O2. The kinetics of repair of single-strand breaks although slightly different for the three cell lines also does not provide a full explanation for the different sensitivity. What was shown to correlate well with the killing effect was the yield of strand breaks produced by H2O2 in the DNA of cells from the three species. A similar H2O2 concentration produced 5-10-times more strand breaks in human DNA than in hamster DNA and 2-4-times more than in mouse DNA. This ratio holds for different cell lines from human and hamster and thus seems to be species-specific. Based on our previous findings we propose that this difference may lie in the amount of chromatin-bound iron and the level of superoxide ion in these cells.

Fetal source extraction from magnetocardiographic recordings by dependent component analysis.

Fetal magnetocardiography (fMCG) has been extensively reported in the literature as a non-invasive, prenatal technique that can be used to monitor various functions of the fetal heart. However, fMCG signals often have low signal-to-noise ratio (SNR) and are contaminated by strong interference from the mother's magnetocardiogram signal. A promising, efficient tool for extracting signals, even under low SNR conditions, is blind source separation (BSS), or independent component analysis (ICA). Herein we propose an algorithm based on a variation of ICA, where the signal of interest is extracted using a time delay obtained from an autocorrelation analysis. We model the system using autoregression, and identify the signal component of interest from the poles of the autocorrelation function. We show that the method is effective in removing the maternal signal, and is computationally efficient. We also compare our results to more established ICA methods, such as FastICA.

Anomalous diffusion process applied to magnetic resonance image enhancement.

Diffusion process is widely applied to digital image enhancement both directly introducing diffusion equation as in anisotropic diffusion (AD) filter, and indirectly by convolution as in Gaussian filter. Anomalous diffusion process (ADP), given by a nonlinear relationship in diffusion equation and characterized by an anomalous parameters q, is supposed to be consistent with inhomogeneous media. Although classic diffusion process is widely studied and effective in various image settings, the effectiveness of ADP as an image enhancement is still unknown. In this paper we proposed the anomalous diffusion filters in both isotropic (IAD) and anisotropic (AAD) forms for magnetic resonance imaging (MRI) enhancement. Filters based on discrete implementation of anomalous diffusion were applied to noisy MRI T2w images (brain, chest and abdominal) in order to quantify SNR gains estimating the performance for the proposed anomalous filter when realistic noise is added to those images. Results show that for images containing complex structures, e.g. brain structures, anomalous diffusion presents the highest enhancements when compared to classical diffusion approach. Furthermore, ADP presented a more effective enhancement for images containing Rayleigh and Gaussian noise. Anomalous filters showed an ability to preserve anatomic edges and a SNR improvement of 26% for brain images, compared to classical filter. In addition, AAD and IAD filters showed optimum results for noise distributions that appear on extreme situations on MRI, i.e. in low SNR images with approximate Rayleigh noise distribution, and for high SNR images with Gaussian or non central χ noise distributions. AAD and IAD filter showed the best results for the parametric range 1.2 < q < 1.6, suggesting that the anomalous diffusion regime is more suitable for MRI. This study indicates the proposed anomalous filters as promising approaches in qualitative and quantitative MRI enhancement.