Long chain capsaicin analogues synthetized by CALB-CLEAs show cytotoxicity on glioblastoma cell lines.

Glioblastoma is one of the most lethal tumors, displaying striking cellular heterogeneity and drug resistance. The prognosis of patients suffering from glioblastoma after 5 years is only 5%. In the present work, capsaicin analogues bearing modifications on the acyl chain with long-chain fatty acids showed promising anti-tumoral activity by its cytotoxicity on U-87 and U-138 glioblastoma multiforme cells. The capsaicin analogues were enzymatically synthetized with cross-linked enzyme aggregates of lipase B from Candida antarctica (CALB). The catalytic performance of recombinant CALB-CLEAs was compared to their immobilized form on a hydrophobic support. After 72 h of reaction, the synthesis of capsaicin analogues from linoleic acid, docosahexaenoic acid, and punicic acid achieved a maximum conversion of 69.7, 8.3 and 30.3% with CALB-CLEAs, respectively. Similar values were obtained with commercial CALB, with conversion yields of 58.3, 24.2 and 22% for capsaicin analogues from linoleic acid, DHA and punicic acid, respectively. Olvanil and dohevanil had a significant cytotoxic effect on both U-87 and U-138 glioblastoma cells. Irrespective of the immobilization form, CALB is an efficient biocatalyst for the synthesis of anti-tumoral capsaicin derivatives. KEY POINTS: • This is the first report concerning the enzymatic synthesis of capsaicin analogues from docosahexaenoic acid and punicic acid with CALB-CLEAs. • The viability U-87 and U-138 glioblastoma cells was significantly affected after incubation with olvanil and dohevanil. • Capsaicin analogues from fatty acids obtained by CALB-CLEAs are promising candidates for therapeutic use as cytotoxic agents in glioblastoma cancer cells.

Development of a rapid assay for ß-etherase activity using a novel chromogenic substrate.

Biocatalytic processes play a crucial role in the valorization of lignin; therefore, methods enabling the monitoring of enzymes such as ß-etherases, capable of breaking ß-O-4 aryl-ether bonds, are of significant biotechnological interest. A novel method for quantifying ß-etherase activity was developed based on the ß-ester bond formation between a chromophore and acetovainillone. The chromogenic substrate ß-(ρ-nitrophenoxy)-α-acetovanillone (PNPAV), was chemically synthesized. Kintetic monitoring of ρ-nitrophenolate release at 410 nm over 10 min, using recombinant LigF from Sphingobium sp SYK-6, LigF-AB and LigE-AB from Althererytrobacter sp B11, yielded enzimatic activities of 404. 3 mU/mg, 72 mU/mg, and 50 mU/mg, respectively. This method is applicable in a pH range of 7.0-9.0, with a sensitivity of up to 50 ng of enzyme, exhibiting no interference with lipolytic, glycolytic, proteolytic, and oxidoreductase enzymes.

Recombinant p40 Protein Promotes Expression of Occludin in HaCaT Keratinocytes: A Brief Communication.

The ability of epithelial barriers to perform as the first defense line against external damage derives from tight junctions, protein complexes that block microorganisms through the paracellular space. Indeed, disturbances of barrier permeability caused by bacterial metabolites and other inflammatory stimuli are the consequence of changes in protein expression in these complexes. Postbiotics, molecules derived from bacteria with beneficial effects on the host, improve barrier function through the activation of survival pathways in epithelial cells. Lacticaseibacillus rhamnosus GG secretes the muramidase p40, which protects intestinal barriers through an EGFR-dependent pathway. In this work, we cloned, expressed, and purified the recombinant p40 protein from L. rhamnosus GR-1 to evaluate its effect on cell viability, cell cytotoxicity, TEER, and protein levels of tight junctions, as well as EGFR activation via Western blot on HaCaT keratinocytes subjected to LPS. We found a novel mutation at residue 368 that does not change the structure of p40. Our protein also reduces the LPS-induced increase in cell cytotoxicity when it is added prior to this stimulus. Furthermore, although LPS did not cause changes in barrier function, p40 increased TEER and occludin expression in HaCaT, but unlike previous work with p40 from LGG, we found that recombinant p40 did not activate EGFR. This suggests that recombinant p40 enhances epithelial barrier function through distinct signaling pathways.

Protocol to Induce the Temporary Opening of the Blood-Brain Barrier with Short-Time Focused Ultrasound in Rats.

Brain neurodegenerative diseases are central nervous system (CNS) affections typically common in older adults. A new therapeutic approach for them consists of providing specific drugs to the CNS through blood circulation; however, the Blood-Brain Barrier (BBB) prevents almost 100% of neurotherapeutics from reaching the brain. There are indications that Focused Ultrasound (FUS), temporarily placed in the BBB, can achieve a controlled increase in temperature at its focus, allowing temporary, localized, and reversible opening of this barrier, which facilitates the temporary delivery of specific drugs. This work presents a FUS-based protocol for the local, temporary, and reversible opening of the BBB in Wistar rats. The proposed protocol specifies certain power, treatment times, and duty cycle to controllably increase the temperature at the region of interest, i.e., the substantia nigra. Numerical simulations using commercial software based on the finite element method were carried out to determine the optimal size of the craniotomies for nearly full-acoustic transmission. Experiments in rats were performed with the parameters used during computational simulations to determine the adequate opening of the BBB. For this, craniotomies of different sizes were made at coordinates of the substantia nigra, and FUS was applied from the exterior. The opening of the BBB was evaluated using Evans Blue (EB) as an indicator of the crossing of the dye from the blood vessels to brain tissue. Numerical simulations demonstrated a major distance reached by the ultrasound focus with a bigger diameter. Experimental results show the local, temporary, and reversible opening of the BBB through a 10 mm diameter craniotomy, which effectively allowed placing the ultrasound focus over the substantia nigra, unlike a 6 mm diameter craniotomy in which there is a deviation of the focus through that window. Moreover, from these results, it was also determined that the disruption of the BBB was reversible, with an opening duration of 6 h after FUS application. The experimental work developed in this study resulted in a minimally invasive method for the temporary opening of the BBB.

Digestive glycosidases from cannonball jellyfish (Stomolophus sp. 2): identification and temporal-spatial variability.

Jellyfish are economically important organisms in diverse countries, carnivorous organisms that consume various prey (crustaceans, mollusks, bivalves, etc.) and dissolved carbohydrates in marine waters. This study was focused on detecting and quantifying the activity of digestive glycosidases from the cannonball jellyfish (Stomolophus sp. 2) to understand carbohydrate digestion and its temporal-spatial variation. Twenty-three jellyfish gastric pouches were collected in 2015 and 2016 in the Gulf of California in three localities (Las Guásimas, Hermosillo, and Caborca). Nine samples were in intra-localities from Las Guásimas. Chitinase (Ch), ß-glucosidase (ß-glu), and ß-N-acetylhexosaminidase (ß-NAHA) were detected in the gastric pouches. However, cellulase, exoglucanase, α-amylase, polygalacturonase, xylanase, and κ-carrageenase were undetected. Detected enzymes showed halotolerant glycolytic activity (i = 0-4 M NaCl), optimal pH, and temperature at 5.0 and 30-50 °C, respectively. At least five ß-glucosidase and two ß-N-acetylhexosaminidase were detected using zymograms; however, the number of proteins with chitinase activity is not precise. The annual variation of cannonball jellyfish digestive glycosidases from Las Guásimas between 2015-2016 does not show significant differences despite the difference in phytoplankton measured as chlorophyll α (1.9 and 3.4 mg/m3, respectively). In the inter-localities, the glycosidase activity was statistically different in all localities, except for ß-N-acetylhexosaminidase activity between Caborca and Hermosillo (3,009.08 ± 87.95 and 3,101.81 ± 281.11 mU/g of the gastric pouch, respectively), with chlorophyll α concentrations of 2.6, 3.4 mg/m3, respectively. For intra-localities, the glycosidase activity did not show significant differences, with a mean chlorophyll α of 1.3 ± 0.1 mg/m3. These results suggest that digestive glycosidases from Stomolophus sp. 2 can hydrolyze several carbohydrates that may belong to their prey or carbohydrates dissolved in marine waters, with salinity over ≥ 0.6 M NaCl and diverse temperature (4-80 °C) conditions. Also, chlorophyll α is related to glycosidase activity in both seasons and inter-localities, except for chitinase activity in an intra-locality (Las Guásimas).

Cloning, expression, and biochemical characterization of ß-etherase LigF from Altererythrobacter sp. B11.

Lignin, a complex heteropolymer present in plant cell walls, is now recognized as a valuable renewable resource with potential applications in various industries. The lignin biorefinery concept, which aims to convert lignin into value-added products, has gained significant attention in recent years. ß-etherases, enzymes that selectively cleave ß-O-4 aryl ether bonds in lignin, have shown promise in lignin depolymerization. In this study, the ß-etherase LigF from Altererythrobacter sp. B11 was cloned, expressed, purified, and biochemically characterized. The LigF-AB11 enzyme exhibited optimal activity at 32 °C and pH 8.5 when catalyzing the substrate PNP-AV. The enzyme displayed mesophilic behavior and demonstrated higher activity at moderate temperatures. Stability analysis revealed that LigF-AB11 was not thermostable, with a complete loss of activity at 60 °C within an hour. Moreover, LigF-AB11 exhibited excellent pH stability, retaining over 50 % of its activity after 1 h under pH conditions ranging from 3.0 to 11.0. Metal ions and surface impregnation agents were found to affect the enzyme's activity, highlighting the importance of considering these factors in enzymatic processes for lignin depolymerization. This study provides valuable insights into the biochemical properties of LigF-AB11 and contributes to the development of efficient enzymatic processes for lignin biorefineries. Further optimization and understanding of ß-etherases will facilitate their practical application in the valorization of lignin.

Identification, Antioxidant Capacity, and Matrix Metallopeptidase 9 (MMP-9) In Silico Inhibition of Haloarchaeal Carotenoids from Natronococcus sp. and Halorubrum tebenquichense.

Natural pigments from haloarchaea are of great interest; bacterioruberin is the major pigment, it shows higher antioxidant power when compared with ß-carotene. However, characterization of bacterioruberin and its isomers along with its antioxidant and the matrix metallopeptidase 9 (MMP-9) inhibition activities in extracts from Natronoccoccus sp. TC6 and Halorubrum tebenquichense SU10 was not previously described, being the aim of this work. The carotenoids profile was performed by UV-Vis spectrophotometry, thin-layer chromatography, nuclear magnetic resonance spectroscopy, and high-resolution mass spectrometry (UPLC-ESI-MS/MS). Antioxidant capacity was determined for DPPH, ABTS, and FRAP. In addition, MMP-9 inhibition was studied using docking simulations. The carotenoid profile of studied strains was composed of bacterioruberin, some derivatives like mono, bis, and tris anhydrobacterioruberin, and also some bacterioruberin cis isomers. The carotenoid pools showed antioxidant capacity for DPPH > ABTS > FRAP; Natronococcus sp. TC6 carotenoid pool was better for ABTS and DPPH, while Halorubrum tebenquichense SU10 carotenoid pool was better for FRAP. Additionally, docking and molecular dynamics suggest that bacterioruberin inhibits MMP-9 through hydrophobic interactions near the catalytic site. Bacterioruberin shows the higher binding energy of -8.3 (kcal/mol). The carotenoids profile of both strains was elucidated, their antioxidant activity and singular participation of each carotenoid on MMP-9 in silico inhibition were evaluated.

Reclassification of the HPGD p.Ala13Glu variant causing primary hypertrophic osteoarthropathy.

Here, we highlight the case of a 31-yr-old man who had clinical features of primary hypertrophic osteoarthropathy (PHOAR) and harbored a homozygous variant (c.38C > A, p.Ala13Glu) in the HPGD gene, as indicated by whole-exome sequencing (WES). This variant has been previously classified by our laboratory as a variant of uncertain significance (VUS). However, another patient with the same phenotype and the same homozygous variant in HPGD was subsequently reported. In reassessing the variant, the absence of this variant in the gnomAD population database, supporting computational predictions, observation in homozygosity in two probands, and specificity of the phenotype for HPGD, all provide sufficient evidence to reclassify the HPGD c.38C > A, p.Ala13Glu variant as likely pathogenic.

Obtaining of Mg-Zn Co-Doped GaN Powders via Nitridation of the Ga-Mg-Zn Metallic Solution and Their Structural and Optical Properties.

Mg-Zn co-dopedGaN powders via the nitridation of a Ga-Mg-Zn metallic solution at 1000 °C for 2 h in ammonia flow were obtained. XRD patterns for the Mg-Zn co-dopedGaN powders showed a crystal size average of 46.88 nm. Scanning electron microscopy micrographs had an irregular shape, with a ribbon-like structure and a length of 8.63 µm. Energy-dispersive spectroscopy showed the incorporation of Zn (Lα 1.012 eV) and Mg (Kα 1.253 eV), while XPS measurements showed the elemental contributions of magnesium and zinc as co-dopant elements quantified in 49.31 eV and 1019.49 eV, respectively. The photoluminescence spectrum showed a fundamental emission located at 3.40 eV(364.70 nm), which was related to band-to-band transition, besides a second emission found in a range from 2.80 eV to 2.90 eV (442.85-427.58 nm), which was related to a characteristic of Mg-doped GaN and Zn-doped GaN powders. Furthermore, Raman scattering demonstrated a shoulder at 648.05 cm-1, which could indicate the incorporation of the Mg and Zn co-dopants atoms into the GaN structure. It is expected that one of the main applications of Mg-Zn co-doped GaN powders is in obtaining thin films for SARS-CoV-2 biosensors.

Cariogenic diet consumption during lockdown.

BACKGROUND: During stressful situations such as pandemic-associated lockdowns, individuals' diets may change towards (cariogenic) 'comfort food'. This study assessed the dietary patterns during the lockdown in the Colombian population. METHODS: A cross-sectional online survey was designed. A convenience sample of 489 adults was drawn, with 50% of them being in COVID-19 lockdown and the other being not or only partially in lockdown. The questionnaire collected data about the type and frequency of food consumed, with a special focus on cariogenic (i.e., rich in free sugars and starches) food. Descriptive analyses were performed, and a generalised linear model was estimated to predict the frequency of cariogenic diet consumption in this period of time. RESULTS: Sweet whole wheat bread (38.2%, p = 0.005), flavoured milk (26.4%, p = 0.002), sugar-sweetened bubble gums (39.8%, p = 0.001), toffees (35.4%, p = 0.004), soft candies (e.g., gums) (35.4%, p = 0.018), chocolates (55.3%, p = 0.017), filled doughnuts (28.5%, p = 0.013) or grapes (51.2%, p = 0.002) were significantly consumed more during the lockdown. Multivariable generalised linear modelling showed being single, having children and being in lockdown were significantly associated with higher frequency of cariogenic food consumption. CONCLUSIONS: Lockdown was found to be associated with detrimentally altered food consumption patterns and, specifically, a more cariogenic diet. Healthcare professionals should consider this when reopening services, and political decision-makers may want to reflect on the unwarranted side effect of lockdown.

Isotherm Theoretical Study of the AlxGa1-xAsySb1-y Quaternary Alloy Using the Regular Solution Approximation for Its Possible Growth via Liquid-Phase Epitaxy at Low Temperatures.

This work presents the theoretical calculation of isotherm diagrams for quaternary alloys of III-V semiconductor compounds with the form IIIxIII1-xVyV1-y. In particular, the isotherm diagrams for the AlxGa1-xAsySb1-y quaternary alloy at low temperatures were calculated (500 °C, 450 °C, 400 °C, and 350 °C). The AlxGa1-xAsySb1-y quaternary alloy was formed from four binary compounds such as GaAs, AlAs, AlSb, and GaSb, all with direct bandgaps. The regular solution approximation was used to find the quaternary isotherm diagrams, represented in four linearly independent equations, which were solved using Parametric Technology Corporation Mathcad 14.0 software for different arsenic and antimony atomic fractions. The results support the possible growth of layers via liquid-phase epitaxy in a range of temperatures from 500 °C to 350 °C, where the crystalline quality could be improved at low temperatures. These semiconductor layers could have applications for optoelectronic devices in photonic communications, thermophotovoltaic systems, and microwave devices with good crystalline quality.

Bioactividad e identificación de los ácidos grasos de la esponja marina Tetilla rodriguesi (Tetractinellida: Tetillidae) en el Caribe colombiano / Bioactivity and identification of fatty acids of the marine sponge Tetilla rodriguesi (Tetractinellida: Tetillidae) in the Colombian Caribbean

Resumen Introducción: Durante millones de años, los organismos marinos han venido desarrollando estrategias para adaptarse a los cambios ambientales y con esto, sintetizando una gran variedad de metabolitos secundarios con actividades biológicas. Objetivo: Evaluar las actividades antimicrobiana y antioxidante e identificar los ácidos grasos del extracto metanólico de la esponja marina Tetilla rodriguesi recolectada en la bahía de Cispatá. Métodos: Los especímenes de T. rodriguesi se sometieron a extracción para obtener el extracto metanólico, del cual se obtuvieron los ácidos grasos que fueron esterificados e identificados haciendo uso de técnicas cromatográficas. Con el extracto metanólico se realizó la actividad antioxidante frente a los radicales ABTS+• y DPPH• y la actividad antimicrobiana por el método de microdilución frente a cepas de referencia de Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis y Candida albicans; además de aislados clínicos de Candida albicans (obtenida en sangre) y Candida krusei (obtenida en catéter). Resultados: Los resultados arrojaron la identificación de 19 ácidos grasos de diferente naturaleza. En el análisis de la actividad antioxidante se pudo encontrar, que la inhibición de los radicales evaluados fue moderada (296.98 ppm para ABTS+• y 3 523.62 ppm para DPPH•). La evaluación de la actividad antimicrobiana mostró, que el extracto metanólico de T. rodriguesi logró reducir en gran medida el crecimiento de todos los microorganismos evaluados. Conclusión: A pesar de que los poríferos tienden a poseer ácidos grasos de gran tamaño, en este trabajó no se encontró la presencia de ácidos grasos de cadena carbonada mayor a 20 miembros. Los resultados de la actividad antioxidante, se asemejan en gran medida al encontrado en otras especies del mismo phylum. En esta investigación, se pudo establecer que el extracto metanólico de T. rodriguesi logró disminuir en gran medida el crecimiento de todas las cepas bacterianas y fúngicas utilizadas.

Abstract Introduction: For millions of years, organisms that inhabit the marine environment have been developing strategies to adapt to environmental changes and with this, synthesizing a great variety of secondary metabolites with biological activities. Objective: Evaluate the antimicrobial and antioxidant activities and identify the fatty acids of the methanolic extract of the marine sponge Tetilla rodriguesi collected in Cispatá bay, Colombian Caribbean. Methods: T. rodriguesi specimens were subjected to extraction to obtain the methanolic extract, of which the fatty acids were obtained, esterified and identified it using chromatographic techniques. With the methanolic extract, the antioxidant activity was carried out against the radicals ABTS+• and DPPH•, and the antimicrobial activity by the microdilution method against reference strains of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis and Candida albicans; in addition to clinical isolates of Candida albicans (obtained in blood) and Candida krusei (obtained in catheter). Result: The results yielded the identification of 19 fatty acids of different nature. In the analysis of the antioxidant activity could be found that inhibition of radical evaluated was moderate (296.98 ppm for ABTS+• and 3 523.62 ppm for DPPH•). The evaluation of antimicrobial activity showed that the methanol extract of T. rodriguesi managed to greatly reduce the growth of all microorganisms tested. Conclusions: Despite the fact that porifers tend to have large fatty acids, in this study the presence of fatty acids with a carbon chain greater than 20 members was not found. The result of antioxidant activity is largely resembled that found in other species of the same phylum. In this research, it was established that the methanolic extract of T. rodriguesi managed to greatly reduce the growth of all the bacterial and fungal strains used.

Mycobacterium leprae Infection in a Wild Nine-Banded Armadillo, Nuevo León, Mexico.

Nine-banded armadillos (Dasypus novemcinctus) are naturally infected with Mycobacterium leprae and are implicated in the zoonotic transmission of leprosy in the United States. In Mexico, the existence of such a reservoir remains to be characterized. We describe a wild armadillo infected by M. leprae in the state of Nuevo León, Mexico.

Potential benefits of structured lipids in bulk compound chocolate: Insights on bioavailability and effect on serum lipids.

The bioavailability impact of serum lipids in compound chocolate products based on structured lipids was studied. Compound chocolate products containing fat with and without structured lipids were digested in vitro under simulated gastrointestinal lipolysis conditions and were studied in vivo in healthy C57BL/6J mice. The in vitro digestion results show that products containing structured lipids, milk compound chocolate filling and white compound coating, significantly reduced the release rate of Free Fatty Acids (FFA) and improved the caloric reduction between 12.49% and 13.71% compared to products without structured lipids, suggesting that FFA were not absorbed. Animal feeding studies revealed no adverse effects on the compound products intake; in fact, these products reduced total cholesterol, LDL-c, VLDL-c and triacylglycerols. The present work shows the relevance of developing functional compound chocolate as providing a potential healthy initiative through the biological effect of the bioactive ingredients incorporated.

Factors associated with the desire to undergo post-mastectomy breast reconstruction in a Mexican breast cancer center.

PURPOSE: To assess the proportion of breast cancer patients treated with total mastectomy who are interested in undergoing breast reconstruction, the factors associated with their desire to undergo this procedure, and the motives stated for their decision. METHODS: Women with stage I-III breast cancer, public health insurance, and history of total mastectomy treated at a center in Monterrey, Mexico, were invited to answer a series of questionnaires regarding their clinical and demographic characteristics, information received about breast reconstruction, body image, and relationship satisfaction. RESULTS: A total of 100 patients were interviewed, of which 68% desired to undergo breast reconstruction. Only 35% recalled talking about this procedure with a physician and 85% claimed not to have enough information to make an informed decision. Those who desired breast reconstruction were younger (p < 0.001), more likely to be in a relationship (p = 0.025), and had a higher probability of having talked to a physician about the procedure (p = 0.019). Furthermore, they felt less sexually attractive (p < 0.001), more deformed (p = 0.006), and less feminine (p = 0.005) since the mastectomy. The main motives to undergo this procedure were to have breast symmetry and greater freedom on which clothes to wear, while the main deterrent was the high economical cost. CONCLUSIONS: Insufficient information about the procedure and high economical cost were identified as potential barriers to undergo breast reconstruction. The findings of this study emphasize the pressing need to optimize patient care by providing information in a standardized manner and improving access to breast reconstruction within the Mexican public healthcare system.

Cannonball jellyfish digestion: an insight into the lipolytic enzymes of the digestive system.

The digestive system and metabolism of the cannonball jellyfish Stomolophus sp. 2 are not well-known. The digestion study was critical to explain its ecology and bloom success. Different enzymes are involved in food digestion, which hydrolyze carbohydrates, proteins, and lipids. This study detected lipolytic activity in enzymatic extracts from gastric pouches of Stomolophus sp. 2 collected in the summer of 2013 at Bahía de Kino, Sonora, México (28°47'47″N 111°57'25″W). Lipase/esterase activity showed optimal pH at 11.0 and 50-60 °C with a half-life (t1/2) of 33 min at 55 °C, whereas halotolerance of this activity was recorded from 0-4 M NaCl. Metal ions Ca2+ and Mn2+ did not affect the activity, but Mg2+ decreased it 14.2% ± 3.15, while chelating agents as ethylenediaminetetraacetic acid reduced the activity 8.55% ± 2.13. Inhibition of lipase/esterase activity with tetrahydrolipstatin and paraoxon-ethyl decreased the activity 18.2% ± 2.3, and 62.80% ± 0.74, respectively, whereas phenylmethanesulfonyl fluoride (a protease inhibitor) did not affect it. The enzyme displayed a higher specificity for short-chain triglycerides, but triolein, coconut oil, olive oil, and fish oil were hydrolyzed. For the first time, phospholipase activity from the gastric pouch of Stomolophus sp. 2 was detected using L-α-phosphatidylethanolamine from chicken egg yolk as a substrate. These results suggest that Stomolophus sp. 2 hydrolyze several kinds of lipids, and lipolytic enzymes are active at alkaline pH under different saline conditions, which may be essential to digest different preys.

A sensitive pH indicator-based spectrophotometric assay for PHB depolymerase activity on microtiter plates.

A continuous spectrophotometric assay for the screening of PHB depolymerase activity in microtiter plates was developed. We evaluated crystalline PHB in the suspension and coated it with the addition of a pH indicator to detect the breakage of the ester bond by proton titration. The reaction rate and the concentration of the recombinant PhaZ1 from Paucimonas lemoignei PHB depolymerase presented a linear correlation. A comparison of the proposed method with the turbidimetric method adapted to the microtiter plates revealed that the use of indicators increases the response signal by at least 5-fold, resulting in increased sensitivity and better signal-to-noise ratio. Furthermore, the proposed method offers a wide range of pH from 5.0 to 9.2 by using different buffer-indicator pairs and was employed for the screening of PHB-depolymerase activity on 140 bacterial strains isolated from Lake Chapala. Eleven strains were positive for PHB-depolymerase activity, which were ACSLRF-27, ACPLRF-6, and ACPLRF-5 (16S rRNA sequence alignment revealed 99-100% similarity with Actinomadura geliboluensis strain A8036, Streptomyces cavourensis strain NRRL 2740, and Streptomyces coelicolor strain DSM 40233, respectively); these that showed the highest activities. In conclusion, the method was successfully applied for finding new strains and for quantifying the PHB depolymerases activity with crystalline PHB.

Screening of Gastrointestinal Lipase Inhibitors Produced by Microorganisms Isolated from Soil and Lake Sediments.

Gastrointestinal lipase inhibitors are molecules of pharmaceutical interest due to their use as anti-obesity drugs. In this study, forty strains isolated from soil and sediments were identified with the ability to produce inhibition of gastrointestinal lipase activity. The biomass extract of these strains showed at least 50% inhibition in the hydrolysis of tributyrin by recombinant human pancreatic lipase (rHPL) or rabbit gastric lipase (RGL) by in vitro assays. Based on gene sequencing, the isolates were identified mainly as Streptomycetes. Moreover, none of the identified strains has been reported to be lipase inhibitor producers, so they can be viewed as potential sources for obtaining new drugs. IC50 values of the three best inhibitor extracts showed that AC104-10 was the most promising strain for production of gastrointestinal lipase inhibitors. AC104-10 shows 99% homology (16S rRNA gene fragment) to Streptomyces cinereoruber strain NBRC 12756. An inhibitory study over trypsin activity revealed that AC104-10 extract, as well as THL, had no significant effect on the activity of this protease, showing its specificity for lipases. In addition, analyzes by MALDI-TOF mass spectrometry of the enzyme-inhibitor complex revealed that there is a covalent interaction of the AC104-10 inhibitor with the catalytic serine of the pancreatic lipase, and that the molecular weight of the inhibitor is approximately 686.19 Da.

Paragonimiasis pulmonar. Reporte de caso pediátrico / Pulmonary paragonimiasis. Pediatric case report

La paragonimiasis es una parasitosis provocada por varias especies de Paragonimus, un trematodo que se transmite a través del consumo de cangrejos poco cocidos o crudos y que se ha encontrado en áreas tropicales y subtropicales de América, Asia y África. Esta infección afecta, principalmente, los pulmones y provoca manifestaciones clínicas y radiológicas muy similares a la tuberculosis pulmonar, por lo cual siempre debe incluirse dentro del diagnóstico diferencial. Se presenta el caso de una niña escolar de 7 años de edad, hospitalizada con el diagnóstico de paragonimiasis pulmonar, quien presentó evolución favorable luego de recibir tratamiento con triclabendazol.

Paragonimiasis is a parasite infection caused by several species of Paragonimus, a trematode that is transmitted through the consumption of raw or undercooked crabs and that has been found in the subtropical areas of America, Asia and Africa. This infection mainly affects the lungs, causing clinical and radiological manifestations very similar to pulmonary tuberculosis, so it should always be included in the differential diagnosis. We present the case of a 7-year-old school patient, hospitalized with the diagnosis of pulmonary paragonimiasis, who had a favorable evolution after receiving treatment with triclabendazole.

[Pulmonary paragonimiasis. Pediatric case report]. / Paragonimiasis pulmonar. Reporte de caso pediátrico.

Paragonimiasis is a parasite infection caused by several species of Paragonimus, a trematode that is transmitted through the consumption of raw or undercooked crabs and that has been found in the subtropical areas of America, Asia and Africa. This infection mainly affects the lungs, causing clinical and radiological manifestations very similar to pulmonary tuberculosis, so it should always be included in the differential diagnosis. We present the case of a 7-year-old school patient, hospitalized with the diagnosis of pulmonary paragonimiasis, who had a favorable evolution after receiving treatment with triclabendazole.

La paragonimiasis es una parasitosis provocada por varias especies de Paragonimus, un trematodo que se transmite a través del consumo de cangrejos poco cocidos o crudos y que se ha encontrado en áreas tropicales y subtropicales de América, Asia y África. Esta infección afecta, principalmente, los pulmones y provoca manifestaciones clínicas y radiológicas muy similares a la tuberculosis pulmonar, por lo cual siempre debe incluirse dentro del diagnóstico diferencial. Se presenta el caso de una niña escolar de 7 años de edad, hospitalizada con el diagnóstico de paragonimiasis pulmonar, quien presentó evolución favorable luego de recibir tratamiento con triclabendazol.