A new species of Diolcogaster (Hymenoptera: Braconidae) from Brazil of potential use in the biological control of the pest Hypercompe brasiliensis (Stoll) (Lepidoptera: Erebidae).

Species of Diolcogaster parasitize Lepidoptera pests of commercial plants. The diversity of this genus is high, but few species of Diolcogaster have been described. The description of a new Diolcogaster species provides information for the biological control using this insect. This study presents the description and key notes on the biology of a new Diolcogaster parasitoid wasp. This species was reared from a caterpillar of Hypercompe brasiliensis collected after feeding on a Gloxinia perennis plant important to floriculture. Two complementary identification analyzes were performed on Diolcogaster adult bodies. The first was the analyses of its external morphology and the second its molecular analysis (mitochondrial DNA). The morphological analysis defined the insect as a new species of Diolcogaster, named Diolcogaster joanesi sp. nov. A maximum-likelihood (ML) analysis partially confirmed the morphological analysis, placing D. joanesi within a cluster including a previously identified species (Diolcogaster choi) and seven other morphospecies. The proximity of D. joanesi to D. choi is discussed and an updated key for all New World species of the xanthaspis group is provided. Twenty-eight adult wasps were obtained (22 females and six males) out of 50 cocoons which larvae emerged from the caterpillar host. The findings contribute to the broader understanding of Diolcogaster in the Neotropics and its potential for the biological control of lepidopteran defoliators.

Intraoperative circulatory arrest secondary to high-risk pulmonary embolism. Case series and updated literature review.

BACKGROUND: Intraoperative pulmonary embolism (PE) with cardiac arrest (CA) represents a critical and potentially fatal condition. Available treatments include systemic thrombolysis, catheter-based thrombus fragmentation or aspiration, and surgical embolectomy. However, limited studies are focused on the optimal treatment choice for this critical condition. We present a case series and an updated review of the management of intraoperative CA secondary to PE. METHODS: A retrospective review of patients who developed high-risk intraoperative PE was performed between June 2012 and June 2022. For the updated review, a literature search on PubMed and Scopus was conducted which resulted in the inclusion of a total of 46 articles. RESULTS: A total of 196 174 major non-cardiac surgeries were performed between 2012 and 2022. Eight cases of intraoperative CA secondary to high-risk PE were identified. We found a mortality rate of 75%. Anticoagulation therapy was administered to one patient (12.5%), while two patients (25%) underwent thrombolysis, and one case (12.5%) underwent mechanical thrombectomy combined with thrombus aspiration. Based on the literature review and our 10-year experience, we propose an algorithm for the management of intraoperative CA caused by PE. CONCLUSION: The essential components for adequate management of intraoperative PE with CA include hemodynamic support, cardiopulmonary resuscitation, and the implementation of a primary perfusion intervention. The prompt identification of the criteria for each specific treatment modality, guided by the individual patient's characteristics, is necessary for an optimal approach.

Evaluación de la función ventricular en la hipertensión pulmonar por resonancia magnética cardíaca / Evaluation of ventricular function in pulmonary hypertension by cardiac magnetic resonance

Resumen Objetivo: Evaluar la función del ventrículo derecho (VD) e izquierdo (VI) en la hipertensión pulmonar (HP) mediante resonancia magnética cardíaca (RMC). Material y métodos: En pacientes con (grupo HP; n = 9) y sin (grupo control; n = 9) HP se evaluó volumen telediastólico (VTD) y telesistólico (VTS) y fracción de eyección (FE) de ventrículo derecho (VD) e izquierdo (VI), área de aurícula derecha (AD) e izquierda y diámetro de arteria pulmonar (AP). Resultados: En HP, el VD presentó mayor VTD y VTS y menor FE (HP 52 ± 5% vs. control 64 ± 2%; p < 0,05). Solo en HP se observó movimiento anormal del tabique interventricular y realce tardío en los puntos de inserción del VD en VI. En HP aumentó el área de AD y el diámetro de AP. En VD, solo en HP, la FE se correlacionó negativamente con VTD (Pearson r: –0,8290; p < 0,01) y VTS (Pearson r: –0,7869; p < 0,05). Conclusiones: La evaluación de pacientes con HP mediante RMC demuestra alteraciones fisiológicas y anatómicas de las cavidades derechas con disminución de la FE del VD que también afecta la interrelación VD/VI. Se recalca la importancia de una evaluación temprana y secuencial del VD con RMC para valorar la mejor estrategia terapéutica para cada caso en particular.

Abstract Objective: To evaluate the function of the right ventricle (RV) and left ventricle (LV) in pulmonary hypertension (PH) through cardiac magnetic resonance imaging (CMR). Material and method: In patients with (PH group; n = 9) and without PH (control group; n = 9), end-diastolic volume (EDV) and end-systolic volume (ESV) and ejection fraction (EF) of right (RV) and left (LV) ventricle, area of the right (RA) and left (LA) atrium and diameter of the pulmonary artery (PA) were evaluated. Results: In PH, the RV increased EDV and ESV and decreased EF (PH: 52 ± 5% vs. control: 64 ± 2%; p < 0.05). Abnormal movement of the interventricular septum and late enhancement in the insertion points of the RV in the LV were only observed in HP. HP increased the area of RA and the diameter of PA. In LV, only in HP, EF was negatively correlated with EDV (Pearson r: –0.8290; p < 0.01) and ESV (Pearson r: –0.7869; p < 0.05). Conclusions: CMR evaluation of patients with PH demonstrates physiological and anatomical alterations of the right cavities with decreased EF in RV that also affects the RV/LV interrelationship. The importance of an early and sequential evaluation of the RV with CMR is emphasized to assess the best therapeutic strategy for each particular case.

Decoding EEG rhythms offline and online during motor imagery for standing and sitting based on a brain-computer interface.

Motor imagery (MI)-based brain-computer interface (BCI) systems have shown promising advances for lower limb motor rehabilitation. The purpose of this study was to develop an MI-based BCI for the actions of standing and sitting. Thirty-two healthy subjects participated in the study using 17 active EEG electrodes. We used a combination of the filter bank common spatial pattern (FBCSP) method and the regularized linear discriminant analysis (RLDA) technique for decoding EEG rhythms offline and online during motor imagery for standing and sitting. The offline analysis indicated the classification of motor imagery and idle state provided a mean accuracy of 88.51 ± 1.43% and 85.29 ± 1.83% for the sit-to-stand and stand-to-sit transitions, respectively. The mean accuracies of the sit-to-stand and stand-to-sit online experiments were 94.69 ± 1.29% and 96.56 ± 0.83%, respectively. From these results, we believe that the MI-based BCI may be useful to future brain-controlled standing systems.

Utilidad de la resonancia magnética cardíaca en pacientes con distrofias neuromusculares (distrofia neuromuscular de Duchene/ Becker) / Usefulness of Cardiac Magnetic Resonance Imaging in Patients with Neuromuscular Dystrophies (Duchenne/Becker Muscular Dystrophy)

RESUMEN Introducción: La Resonancia Magnética Cardíaca (RMC) es cada vez más frecuentemente utilizada en pacientes con Distrofia Neuromuscular de Duchene y Becker (DMD y DMB). Por la capacidad de demostrar realce tardío con gadolinio (RTG), que identifica zonas de fibrosis de la pared media y subepicárdica, subendocárdica o global, y el cálculo de la fracción de eyección ventricular izquierda (FEVI), se considera el patrón oro en el diagnóstico y pronóstico de la afección cardíaca de estas distrofias. Objetivos: Determinar por medio de RMC la presencia de fibrosis cardíaca en pacientes con distrofia neuromuscular. Determinar el compromiso neuromuscular y cardiaco. Definir la evolución cardiovascular de estos pacientes Material y métodos: Se realizó un estudio descriptivo de corte transversal de 16 pacientes consecutivos desde marzo de 2021 a julio de 2022 en el Área de imagen cardiaca de CEMET (Centro Médico Tafi Viejo) y Diagnóstico Médico Dr. Gaya de la provincia de Tucumán. Resultados: Se evaluaron 16 pacientes, todos con diagnóstico confirmado de DMD/DMB por laboratorio, enzimas, y test genéticos. La edad promedio fue 19 años. Todos tenían estadio grave de la escala de Vignos y tratamiento neurológico. Todos tenían tratamiento con betabloqueantes o inhibidores de la enzima de conversión de la angiotensina. La RMC evidenció que 4 pacientes tenían deterioro grave de la FEVI (<35%); 8 pacientes tenían trastornos segmentarios o globales de la motilidad parietal del VI y en 12 se observó RTG, de distribución variable: difusa, mesocárdica, subendocárdica y subepicárdica. En 6 pacientes se observó miocardio no compacto y en 2 derrame pericárdico leve. Conclusión: La RMC debe ser incluida como método de cribaje para pacientes con distrofias neuromusculares. Su aporte para la estadificación clínica y terapéutica es de suma importancia.

ABSTRACT Introduction: Cardiac magnetic resonance imaging (CMR) is commonly used in patients with Duchene (DMD) and Becker (DMB) Neuromuscular Dystrophies. Late gadolinium enhancement (LGE) identifies areas of middle, subepicardial, or subendocardial wall fibrosis, and volumetric left ventricular ejection fraction (LVEF) is considered the gold standard in the diagnosis and prognosis of these dystrophies. Myocardial fibrosis occurs in patients with neuromuscular dystrophies. The purposes of our study were to determine the presence of cardiac fibrosis using CMR, to determine neuromuscular and cardiac involvement, and to evaluate the cardiovascular outcomes of these patients. Methods: A descriptive cross-sectional study of 16 consecutive patients was conducted from March 2021 to July 2022 in the Cardiac Imaging Service of Diagnóstico Médico and CEMET- Tucumán. Results: A total of 16 patients were evaluated, 100% of them with confirmed diagnosis of DMD/DMB by laboratory, enzymes and genetic tests. Mean age was 19 years. All patients had severe stage of the Vignos Scale and were under neurological treatment. All patients were also treated with beta-blockers or angiotensin-converting enzyme inhibitors. CMR revealed severe LVEF impairment <35% in 4 patients, segmental or global left ventricular (LV) wall motion disorders in 8 patients, and variable distribution pattern (diffuse, mesocardial, subendocardial and subepicardial patterns) of LGE in 12 patients. Non-compacted myocardium was observed in 6, and mild pericardial effusions in 2 patients. Conclusion: CMR should be included as a screening method in patients with neuromuscular dystrophies. Its contribution to clinical, echocardiographic and therapeutic staging is of utmost importance.

Machine learning in the loop for tuberculosis diagnosis support.

The use of machine learning (ML) for diagnosis support has advanced in the field of health. In the present paper, the results of studying ML techniques in a tuberculosis diagnosis loop in a scenario of limited resources are presented. Data are analyzed using a tuberculosis (TB) therapy program at a health institution in a main city of a developing country using five ML models. Logistic regression, classification trees, random forest, support vector machines, and artificial neural networks are trained under physician supervision following physicians' typical daily work. The models are trained on seven main variables collected when patients arrive at the facility. Additionally, the variables applied to train the models are analyzed, and the models' advantages and limitations are discussed in the context of the automated ML techniques. The results show that artificial neural networks obtain the best results in terms of accuracy, sensitivity, and area under the receiver operating curve. These results represent an improvement over smear microscopy, which is commonly used techniques to detect TB for special cases. Findings demonstrate that ML in the TB diagnosis loop can be reinforced with available data to serve as an alternative diagnosis tool based on data processing in places where the health infrastructure is limited.

ATLANTIC ANTS: a data set of ants in Atlantic Forests of South America.

Ants, an ecologically successful and numerically dominant group of animals, play key ecological roles as soil engineers, predators, nutrient recyclers, and regulators of plant growth and reproduction in most terrestrial ecosystems. Further, ants are widely used as bioindicators of the ecological impact of land use. We gathered information of ant species in the Atlantic Forest of South America. The ATLANTIC ANTS data set, which is part of the ATLANTIC SERIES data papers, is a compilation of ant records from collections (18,713 records), unpublished data (29,651 records), and published sources (106,910 records; 1,059 references), including papers, theses, dissertations, and book chapters published from 1886 to 2020. In total, the data set contains 153,818 ant records from 7,636 study locations in the Atlantic Forest, representing 10 subfamilies, 99 genera, 1,114 ant species identified with updated taxonomic certainty, and 2,235 morphospecies codes. Our data set reflects the heterogeneity in ant records, which include ants sampled at the beginning of the taxonomic history of myrmecology (the 19th and 20th centuries) and more recent ant surveys designed to address specific questions in ecology and biology. The data set can be used by researchers to develop strategies to deal with different macroecological and region-wide questions, focusing on assemblages, species occurrences, and distribution patterns. Furthermore, the data can be used to assess the consequences of changes in land use in the Atlantic Forest on different ecological processes. No copyright restrictions apply to the use of this data set, but we request that authors cite this data paper when using these data in publications or teaching events.

Detrimental effects of pyriproxyfen on the detoxification and abilities of Belostoma anurum to prey upon Aedes aegypti larvae.

Despite being effective in controlling mosquito larvae and a few other target organisms, the application of insecticides into aquatic systems may cause unintended alterations to the physiology or behavioral responses of several aquatic non-target organisms, which can ultimately lead to their death. Here, we firstly evaluated whether the susceptibility of the giant water bug, Belostoma anurum (Hemiptera: Belostomatidae), a predator of mosquito larvae, to pyriproxyfen would be similar to that of its potential prey, larvae of Aedes aegypti (Diptera: Culicidae). Secondly, we recorded the nominal concentrations of pyriproxyfen in water and evaluated whether sublethal exposures would lead to physiological or behavioral alterations on the B. anurum nymphs. We characterized the activities of three major families of detoxification enzymes (i.e., cytochrome P450 monooxygenases, glutathione-S-transferase, and general esterases) and further evaluated the abilities of pyriproxyfen sublethally-exposed B. anurum to prey upon A. aegypti larvae at different prey densities. Our findings revealed that nominal pyriproxyfen concentration significantly decreased (approximately 50%) over the first 24 h. Furthermore, when applied at the concentration of 10 µg a.i./L, pyriproxyfen was approximately four times more toxic to A. aegypti larvae (LT50 = 48 h) than to B. anurum nymphs (LT50 = 192 h). Interestingly, the pyriproxyfen sublethally-exposed (2.5 µg a.i./L) B. anurum nymphs exhibited reduced enzyme activities (cytochrome P450 monooxygenases) involved in detoxication processes and preyed significantly less on A. aegypti larvae when compared to unexposed predators. Collectively, our findings demonstrate that mortality-based pyriproxyfen risk assessments are not always protective of aquatic non-target organisms.

Índice leucoglucémico como marcador pronóstico de complicaciones en pacientes con infarto agudo de miocardio / Leukoglucemic index as a prognostic marker for complications in patients with acute myocardial infarction

Resumen Introducción:: El índice leucoglucémico es un factor pronóstico, poco conocido y utilizado, que relaciona la glucemia y los leucocitos registrados al ingreso hospitalario. Su importancia radica en la determinación del riesgo de complicaciones y la mortalidad en pacientes con infarto agudo de miocardio. Objetivo: Establecer al índice leucoglucémico como factor predictor de complicaciones durante la evolución intrahospitalaria en los pacientes con infarto agudo de miocardio. Método: Estudio de tipo epidemiológico, analítico, observacional y de corte transversal, en una cohorte de pacientes que ingresaron con infarto agudo de miocardio durante un período de un año y tres meses. Resultados: Se incluyó en el estudio a 205 pacientes con infarto agudo de miocardio, cuyo promedio de edad fue de 62.99 ± 12.2 años, con predominio en varones con 69.3%. El infarto agudo de miocardio con elevación del segmento ST predominó en frecuencia con 63.9% y mayor tasa de complicaciones (p < 0.001). El promedio del índice leucoglucémico fue de 1,578.41 ± 1,208.1 y el punto de corte establecido fue de 656.8, de acuerdo con la curva ROC, con sensibilidad del 95.8% y especificidad del 73% para la predicción de complicaciones intrahospitalarias, con OR de 7.89. Conclusión: Un índice leucoglucémico > 656.8 representa un riesgo de 7.89 veces de desarrollar complicaciones en la población estudiada.

Abstract Introduction: Leukoglycemic index is a poorly known and used prognostic factor that correlates blood glucose and leukocytes which are taken at hospital admission. Its importance lies in determining complications and mortality risks in patients with acute myocardial infarction. Objective: To establish the leukoglycemic index as a predictor of complications during the in-hospital evolution in patients with acute myocardial infarction. Methods: Epidemiological, observational, cross-sectional, crosssectional study on a cohort of patients admitted with acute myocardial infarction during a period of 1 year 3 months. Results: 205 patients with acute myocardial infarction were included in this study. The mean age was 62.99 ± 12.2 years old, more frequently in males by 69.3%. It was determined that acute myocardial infarction with ST elevation predominated both in frequency with 63.9%, as well as with a higher rate of complications (p < 0.001). The average of leukoglycemic index was 1578.41 ± 1208.1 and the cut-off point was 656.8, according to ROC curve, with sensitivity of 95.8% and specificity of 73% for the prediction of inhospital complications, OR 7.89. Conclusions: A leukoglycemic index greater than 656.8 represents a 7.89-fold risk of developing complications in the study population.

Type specimens of Pompiloidea, Thynnoidea and Vespoidea (Hymenoptera) deposited in the Museu de Zoologia da Universidade de São Paulo, Brazil

The Hymenoptera collection of the Museu de Zoologia da Universidade de São Paulo, Brazil (MZSP) houses one of the most important collections for the Brazilian and Neotropical wasp faunas. The present catalogue lists the type specimens of Pompiloidea, Thynnoidea and Vespoidea (Insecta, Hymenoptera) deposited in the MZSP. The collection includes a total of 422 type specimens (66 holotypes, 28 lectotypes, 278 paratypes, 45 paralectotypes, and five syntypes), being 91 Pompiloidea (40 Mutillidae type specimens of 10 genera and 25 species, 51 Pompilidae type specimens of 4 genera and 27 species), 191 Vespoidea (15 genera and 86 species of Vespidae), and 18 Thynnoidea (eight genera and 12 species of Thynnidae). All information written in labels was compiled and is presented along with additional data from the original descriptions, MZSP records and other sources. We provide Specimage links to high-resolution photographs of holotypes and lectotypes at the Hymenoptera image database of the Ohio State University.

Type specimens of Pompiloidea, Thynnoidea and Vespoidea (Hymenoptera) deposited in the Museu de Zoologia da Universidade de São Paulo, Brazil

The Hymenoptera collection of the Museu de Zoologia da Universidade de São Paulo, Brazil (MZSP) houses one of the most important collections for the Brazilian and Neotropical wasp faunas. The present catalogue lists the type specimens of Pompiloidea, Thynnoidea and Vespoidea (Insecta, Hymenoptera) deposited in the MZSP. The collection includes a total of 422 type specimens (66 holotypes, 28 lectotypes, 278 paratypes, 45 paralectotypes, and five syntypes), being 91 Pompiloidea (40 Mutillidae type specimens of 10 genera and 25 species, 51 Pompilidae type specimens of 4 genera and 27 species), 191 Vespoidea (15 genera and 86 species of Vespidae), and 18 Thynnoidea (eight genera and 12 species of Thynnidae). All information written in labels was compiled and is presented along with additional data from the original descriptions, MZSP records and other sources. We provide Specimage links to high-resolution photographs of holotypes and lectotypes at the Hymenoptera image database of the Ohio State University.(AU)

Experimental design of a liposomal lipid system: A potential strategy for paclitaxel-based breast cancer treatment.

Paclitaxel (PTX) is widely used as a first-line treatment for patients with metastatic breast cancer; however, its poor water solubility represents a major challenge for parenteral administration. The encapsulation of the PTX in drug-delivery systems with high affinity for tumor sites could improve the uptake and increase its therapeutic efficacy. In this work, long-circulating and pH-sensitive PEG-coated (SpHL-PTX) and PEG-folate-coated liposomes containing PTX (SpHL-FT-PTX) were prepared, and the physicochemical properties and in vitro cytotoxic activity were evaluated. Both formulations presented adequate physicochemical properties, including a mean diameter smaller than 200 nm, zeta potential values near the neutral range, and an encapsulation percentage higher than 93%. Moreover, SpHL-FT-PTX showed a good stability after storage for 100 days at 4 °C. The viability studies on breast cancer cell lines (MDA-MB-231 and MCF-7) demonstrated cytotoxic activity more pronounced for SpHL-FT-PTX than for SpHL-PTX or free drug for both tumor cell lines. This activity was reduced to a rate comparable to SpHL-PTX when the cells were previously treated with folic acid in order to saturate the receptors. In contrast, in the normal cell line (L929), cell viability was decreased only by free or liposomal PTX in the highest concentrations. A significantly higher selectivity index was obtained after SpHL-FT-PTX treatment compared to SpHL-PTX and free PTX. Therefore, the results of the present work suggest that SpHL-FT-PTX can be a promising formulation for the treatment of metastatic breast cancer.

Encapsulation of cisplatin in long-circulating and pH-sensitive liposomes improves its antitumor effect and reduces acute toxicity.

Cisplatin (CDDP) is one of the most effective and potent anticancer drugs used as first-line chemotherapy against several solid tumors. However, the severe side effects and its tendency to provoke chemoresistance often limit CDDP therapy. To avoid these inconveniences, the present study's research group developed long-circulating and pH-sensitive liposomes containing CDDP (SpHL-CDDP). The present study aimed to evaluate the antitumor effect and toxicity of SpHL-CDDP, as compared with that of free CDDP, and long-circulating and non- pH-sensitive liposomes containing CDDP (NSpHL-CDDP), after their intravenous administration in solid Ehrlich tumor-bearing mice. Antitumor activity was evaluated by analysis of tumor volume and growth inhibition ratio, serum vascular endothelial growth factor (VEGF) levels, and histomorphometric and immunohistochemical studies. Body weight variation and the histological examination of bone marrow and kidneys were used as toxicity indicators. A significant reduction in the tumor volume and a higher tumor growth inhibition ratio was observed after SpHL-CDDP treatment, compared with free CDDP and NSpHL-CDDP treatments. In addition, complete remission of the tumor was detected in 18.2% of the mice treated with SpHL- CDDP (16 mg/kg). As such, the administration of SpHL-CDDP, as compared with free CDDP and NSpHL-CDDP, led to a decrease in the area of necrosis and in the percentage of positive CDC 47 tumor cells. A significant reduction in the VEGF serum level was also observed after SpHL-CDDP treatment, as compared with free-CDDP treatment. SpHL-CDDP administered in a two-fold higher dose than that of free CDDP presented a loss in body weight and changes in the hematopoietic tissue morphology, which proved to be similar to that of free CDDP. No changes could be verified in the renal tissue after any formulations containing CDDP had been administered. These findings showed that SpHL-CDDP allowed for the administration of higher doses of CDDP, significantly improving its antitumor effect.

Acute toxicity study of cisplatin loaded long-circulating and pH-sensitive liposomes administered in mice.

Cisplatin (CDDP) is a very active and cytotoxic agent but causes severe side effects, namely nephrotoxicity, which limits the therapy. The present study aimed to evaluate the acute toxicity of long-circulating and pH-sensitive liposomes containing cisplatin (SpHL-CDDP), as compared to free CDDP, after their intravenous administration in mice. After the administration of free CDDP or SpHL-CDDP at different doses, the body weight was recorded and the LD50 and the maximum tolerated dose (MTD) were calculated. Blood samples were collected for hematological and biochemical analysis. Kidneys, liver, spleen, and bone marrow were removed for histopathological examination. A reduction of body weight of less than 15% could be observed in male and female mice after treatment with free CDDP and SpHL-CDDP at doses of < or = 10 mg/kg and 20 mg/kg, respectively. The LD50 and MTD values obtained after SpHL-CDDP administration were approximately two and three times higher, respectively, than those obtained using free CDDP. Changes in hematological parameters and hematopoietic tissue morphology showed the appearance of toxicity induced by free CDDP. By contrast, the absence of mielotoxicity after SpHL-CDDP treatment could be observed. As regards nephrotoxicity, no alteration in blood urea and creatinine levels, nor morphological change in kidneys, could be observed in mice treated with SpHL-CDDP, as compared to saline-treatment control group. The results showed that SpHL-CDDP at its MTD (20 mg/kg), as compared to the administration of free CDDP at its MTD (7.5 mg/kg), significantly reduced the renal toxicity. Thus, SpHL-CDDP can eliminate CDDP-induced toxicity and is a promising candidate for the intravenous therapy of solid tumors.

Analysis of genetic variability of Plasmodium vivax isolates from different Brazilian Amazon areas using tandem repeats.

Few genetic markers have been described to analyze populations of Plasmodium vivax. The genetic variability of P. vivax has been analyzed mainly among isolates taken from areas ranging from hyper- to holoendemic areas. These studies of genetic variability have neglected many areas with different epidemiologic profiles. The purpose of this study was to analyze the genetic variability of P. vivax isolates from four different Brazilian Amazon areas. We chose to study the five most polymorphic tandem repeats (TRs) identified so far. All TRs studied were polymorphic in at least one studied population, with a modal allele at nearly all loci. Expected heterozygosity ranged from 0.462 to 0.666 and did not correlate with the repeat array length. The genetic distances among the populations varied from 0.027 to 0.241, and did not correlate with their geographic separation. Tandem repeats identified in P. vivax isolates failed to allow geographic clustering.

Immobilization of Candida antarctica lipase B by adsorption to green coconut fiber.

An agroindustrial residue, green coconut fiber, was evaluated as support for immobilization of Candida antarctica type B (CALB) lipase by physical adsorption. The influence of several parameters, such as contact time, amount of enzyme offered to immobilization, and pH of lipase solution was analyzed to select a suitable immobilization protocol. Kinetic constants of soluble and immobilized lipases were assayed. Thermal and operational stability of the immobilized enzyme, obtained after 2 h of contact between coconut fiber and enzyme solution, containing 40 U/ml in 25 mM sodium phosphate buffer pH 7, were determined. CALB immobilization by adsorption on coconut fiber promoted an increase in thermal stability at 50 and 60 degrees C, as half-lives (t (1/2)) of the immobilized enzyme were, respectively, 2- and 92-fold higher than the ones for soluble enzyme. Furthermore, operational stabilities of methyl butyrate hydrolysis and butyl butyrate synthesis were evaluated. After the third cycle of methyl butyrate hydrolysis, it retained less than 50% of the initial activity, while Novozyme 435 retained more than 70% after the tenth cycle. However, in the synthesis of butyl butyrate, CALB immobilized on coconut fiber showed a good operational stability when compared to Novozyme 435, retaining 80% of its initial activity after the sixth cycle of reaction.

Immobilization of Candida antarctica lipase B by covalent attachment to green coconut fiber.

The objective of this study was to covalently immobilize Candida antarctica type B lipase (CALB) onto silanized green coconut fibers. Variables known to control the number of bonds between enzyme and support were evaluated including contact time, pH, and final reduction with sodium borohydride. Optimal conditions for lipase immobilization were found to be 2 h incubation at both pH 7.0 and 10.0. Thermal stability studies at 60 degrees C showed that the immobilized lipase prepared at pH 10.0 (CALB-10) was 363-fold more stable than the soluble enzyme and 5.4-fold more stable than the biocatalyst prepared at pH 7.0 (CALB-7). CALB-7 was found to have higher specific activity and better stability when stored at 5 degrees C. When sodium borohydride was used as reducing agent on CALB-10 there were no improvement in storage stability and at 60 degrees C stability was reduced for both CALB-7 and CALB-10.