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1.
Cell ; 177(7): 1714-1724.e12, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31080063

RESUMO

Arthritogenic alphaviruses, such as Chikungunya virus (CHIKV), cause severe and debilitating rheumatic diseases worldwide, resulting in severe morbidity and economic costs. Recently, MXRA8 was reported as an entry receptor. Here, we present the crystal structures of the mouse MXRA8, human MXRA8 in complex with the CHIKV E protein, and the cryo-electron microscopy structure of human MXRA8 and CHIKV virus-like particle. MXRA8 has two Ig-like domains with unique structural topologies. This receptor binds in the "canyon" between two protomers of the E spike on the surface of the virion. The atomic details at the interface between the two binding entities reveal that both the two domains and the hinge region of MXRA8 are involved in interaction with CHIKV E1-E2 residues from two protomers. Notably, the stalk region of MXRA8 is critical for CHIKV virus entry. This finding provides important information regarding the development of therapeutic countermeasures against those arthritogenic alphaviruses.


Assuntos
Vírus Chikungunya/química , Proteínas de Membrana/química , Proteínas do Envelope Viral/química , Internalização do Vírus , Animais , Vírus Chikungunya/metabolismo , Chlorocebus aethiops , Células HEK293 , Humanos , Proteínas de Membrana/metabolismo , Domínios Proteicos , Células Vero , Proteínas do Envelope Viral/metabolismo
2.
Biosci Biotechnol Biochem ; 87(6): 653-662, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-36972615

RESUMO

Staphylococcus lugdunensis produces lugdulysin, a metalloprotease that may contribute to its virulence. This study aimed to evaluate the biochemical aspects of lugdulysin and investigate its effect on Staphylococcus aureus biofilms. The protease was isolated and characterized for its optimal pH and temperature, hydrolysis kinetics, and influence of metal cofactor supplementation. The protein structure was determined via homology modeling. The effect on S. aureus biofilms was assessed by the micromethod technique. The protease optimal pH and temperature were 7.0 and 37 °C, respectively. EDTA inhibited protease activity, confirming it as a metalloprotease. Lugdulysin activity was not recovered by divalent ion supplementation post-inhibition, and supplementation with divalent ions did not change enzymatic activity. The isolated enzyme was stable for up to 3 h. Lugdulysin significantly inhibited the formation and disrupted preestablished protein-matrix MRSA biofilm. This preliminary study indicates that lugdulysin has a potential role as a competition mechanism and/or modulation of staphylococcal biofilm.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Staphylococcus lugdunensis , Humanos , Staphylococcus aureus , Antibacterianos/farmacologia , Biofilmes , Metaloproteases/farmacologia , Peptídeo Hidrolases , Testes de Sensibilidade Microbiana
3.
J Pept Sci ; 24(11): e3129, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30325566

RESUMO

Eight molecules, four peptides (SPs) and four lipopeptides (LPs) derived by rational design from surfactin, a well-known secreted biosurfactant from Bacillus subtilis, were produced employing Fmoc-based solid-phase synthesis. These new peptides were tested to evaluate their potential biosurfactant and biological activities, aiming at possible applications in industrial, biological, pharmaceutical, and medical use. Five molecules (SP1, SP2, SP4, LP5, and LP8) presented potential for medical uses, mainly due to their drug delivery properties as suggested by their synergistic activity with the antibiotic vancomycin against Staphylococcus aureus. All synthetic peptides showed low toxicity against Vero cell cultures, in assays of hemolysis, and in different cytotoxicity assays. In addition, we found that three peptides (SP1, LP6, and LP7) had potential technological and industrial use because of their emulsifying capacity, low toxicity, and ability to physically stabilize solutions. These novel molecules retained some properties of the parental molecule (surfactin, which was originally obtained through nonribosomal synthesis in Bacillus subtilis) but have the advantage of being linear peptides, which can be produced at large scales through the use of conventional heterologous protein expression protocols.


Assuntos
Bacillus subtilis/metabolismo , Lipopeptídeos/síntese química , Peptídeos Cíclicos/química , Peptídeos/síntese química , Técnicas de Síntese em Fase Sólida/métodos , Animais , Bacillus subtilis/química , Proteínas de Bactérias/química , Chlorocebus aethiops , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Sinergismo Farmacológico , Emulsificantes/síntese química , Emulsificantes/química , Emulsificantes/farmacologia , Humanos , Lipopeptídeos/química , Lipopeptídeos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Vancomicina/farmacologia , Células Vero
4.
Gac Med Mex ; 153(7): 739-746, 2017.
Artigo em Espanhol | MEDLINE | ID: mdl-29414955

RESUMO

Objective: To establish the frequency and results in patients carriers with multiple aneurysms (MA) treated by microsurgery and/or neurological endovascular therapy (NET) in the Hospital of Specialties on The National Medical Center La Raza. Method: It is an ambispective, descriptive and longitudinal study that includes patients carriers of MA treated in the National Medical Center La Raza from March the 1st of 2009 to April the 30th of 2014. Results: 62 patients carriers of 151 aneurysms were treated. According to the type of treatment, 30 patients (49%) were included in the surgical group (GQ), 25 (40%) in the endovascular group (GE) and 7 (11%) in the combinated group (GC). The number of aneurysms was distributed this way: 69 (46%) in the GQ, 61 (40%) in the GE and 21 (14%) in the GC. At GQ, it was not possible to exclude all their aneurysms on 21% of the patients, while it was feasible in only 27%. In all GE patients (40%) the exclusion of all aneurysms was achieved. The GC, meaning surgical cases that were not completed by NET, formed 11% of the cases. At GQ there was a rate of 6% of complications, meanwhile at GE it was 0.5%.


Assuntos
Aneurisma Intracraniano/terapia , Aneurisma Roto/diagnóstico por imagem , Aneurisma Roto/epidemiologia , Aneurisma Roto/terapia , Embolização Terapêutica/métodos , Embolização Terapêutica/mortalidade , Embolização Terapêutica/estatística & dados numéricos , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/mortalidade , Procedimentos Endovasculares/estatística & dados numéricos , Feminino , Hospitais Especializados , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/epidemiologia , Estudos Longitudinais , Masculino , Microcirurgia/mortalidade , Microcirurgia/estatística & dados numéricos , Estudos Prospectivos , Estudos Retrospectivos , Distribuição por Sexo , Stents , Resultado do Tratamento
6.
Gac Med Mex ; 150 Suppl 3: 279-81, 2014 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-25643876

RESUMO

BACKGROUND: Intraventricular hemorrhage (IVH) is one of the most serious complications in premature lightweight. While in the decade of 1970-1980 the incidence was 40-50%, now it is at least 20%. But it presents a challenge because of the multiple existing therapies and the results in terms of neurological sequelae. MATERIAL AND METHODS: We performed a retrospective review of 48 patients managed with ventriculo subgaleal shunt and a therapeutic decision based on gestational age, weight, and grade of intraventricular hemorrhage. RESULTS: Of the patients, 29 (60%) of the cases were female and 19 (40%) were male. The average gestation age for placing the subgaleal system was 30 months, with an average weight of 1,511 g, and with an infection rate of 4%. In 44 cases peritoneal system was placed (92%) because four died (8%). No mortality was observed at surgery. CONCLUSIONS: Mortality in the past appeared in 75% of patients, with the realization that derivation of subgaleal irrigation reduces infections besides allowing proper control of hydrocephalus and thus decreases the long-term neurological sequelae.

7.
Viruses ; 15(4)2023 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-37112983

RESUMO

Rhinoviruses (RVs) are the major cause of common cold, a respiratory disease that generally takes a mild course. However, occasionally, RV infection can lead to serious complications in patients debilitated by other ailments, e.g., asthma. Colds are a huge socioeconomic burden as neither vaccines nor other treatments are available. The many existing drug candidates either stabilize the capsid or inhibit the viral RNA polymerase, the viral proteinases, or the functions of other non-structural viral proteins; however, none has been approved by the FDA. Focusing on the genomic RNA as a possible target for antivirals, we asked whether stabilizing RNA secondary structures might inhibit the viral replication cycle. These secondary structures include G-quadruplexes (GQs), which are guanine-rich sequence stretches forming planar guanine tetrads via Hoogsteen base pairing with two or more of them stacking on top of each other; a number of small molecular drug candidates increase the energy required for their unfolding. The propensity of G-quadruplex formation can be predicted with bioinformatics tools and is expressed as a GQ score. Synthetic RNA oligonucleotides derived from the RV-A2 genome with sequences corresponding to the highest and lowest GQ scores indeed exhibited characteristics of GQs. In vivo, the GQ-stabilizing compounds, pyridostatin and PhenDC3, interfered with viral uncoating in Na+ but not in K+-containing phosphate buffers. The thermostability studies and ultrastructural imaging of protein-free viral RNA cores suggest that Na+ keeps the encapsulated genome more open, allowing PDS and PhenDC3 to diffuse into the quasi-crystalline RNA and promote the formation and/or stabilization of GQs; the resulting conformational changes impair RNA unraveling and release from the virion. Preliminary reports have been published.


Assuntos
Quadruplex G , Rhinovirus , Humanos , Rhinovirus/genética , Oligonucleotídeos , RNA Viral/genética , Pareamento de Bases
8.
J Parasitol ; 109(4): 377-400, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37532252

RESUMO

An updated checklist of adult tapeworms (Platyhelminthes: Cestoda) that parasitize wild North American amphibians and reptiles is presented: A total of 58 species grouped in 15 genera, 5 families, and 3 orders, are registered; these infect a total of 90 species of reptiles and 88 species of amphibians in the region. An illustrated identification key for the families and genera listed is proposed.


Assuntos
Cestoides , Parasitos , Humanos , Animais , Lista de Checagem , Répteis , América do Norte
9.
Cir Cir ; 90(5): 627-631, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36327480

RESUMO

OBJECTIVE: Depressed skull fractures are the result of trauma injuries. They are present in approximately 3% of patients who arrive to an emergency room with skull trauma. The main objective of surgical repair in depressed fractures is correction of cosmetic deformity and the prevention of infections. MATERIAL AND METHODS: A retrospective and transversal study was performed by our department between April 2016 and May 2017. Sixteen patients that underwent a craniotomy for skull trauma with depressed fracture were included in the study. The diagnosis was made by simple cranial CT scan alongside a three-dimensional reconstruction. RESULTS: Of the sixteen patients included, 5 were females (31.2%) and 11 males (68.8%). Twelve of the cases were an exposed fracture. In 7 cases, the fracture was located at parietal bone; 5 were located at frontal bone and 4 at the temporal bone. The average Glasgow coma score in the sample was 13. There were no complications nor deaths. CONCLUSIONS: The remodeling and repositioning of the autologous bone graft allow an adequate cosmetic result and it also avoids the placement of implants without increasing the costs and additional risks.


OBJETIVO: las fracturas de cráneo deprimidas son el resultado de lesiones traumáticas. Se encuentran en aproximadamente el 3% de los pacientes que se presentan en salas de emergencia con traumatismo craneal. El objetivo principal de la reparación quirúrgica en fracturas deprimidas es la corrección de la deformidad cosmética y la prevención de infecciones. PACIENTES Y MÉTODOS: se realizó un estudio retrospectivo y transversal en nuestro departamento entre abril de 2016 y mayo de 2017. Se incluyeron 16 pacientes que se sometieron a una craneotomía por traumatismo craneal y fractura deprimida. El diagnóstico se realizó mediante tomografía computarizada craneal simple con reconstrucción 3D. RESULTADOS: se incluyeron 16 pacientes, 5 casos femeninos (31,2%) y 11 masculinos (68,8%). En 12 casos se observó fractura expuesta. En 7 casos la fractura se localizó en el hueso parietal; 5 casos en el hueso frontal y 4 casos en hueso temporal. El puntaje promedio en la Escala de Coma de Glasgow fue 13. No hubo complicaciones o muertes. CONCLUSIONES: la remodelación y el reposicionamiento del injerto óseo autólogo permite un resultado cosmético adecuado evitando la colocación de implantes sin aumentar los costos y riesgos adicionales.


Assuntos
Traumatismos Craniocerebrais , Fraturas Ósseas , Fratura do Crânio com Afundamento , Masculino , Feminino , Humanos , Fratura do Crânio com Afundamento/cirurgia , Fratura do Crânio com Afundamento/diagnóstico , Estudos Retrospectivos , Craniotomia , Osso Frontal/cirurgia , Traumatismos Craniocerebrais/cirurgia , Instituições Acadêmicas
10.
Int J Biol Macromol ; 222(Pt A): 1015-1026, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183752

RESUMO

Despite the fast development of vaccines, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) still circulates through variants of concern (VoC) and escape the humoral immune response. SARS-CoV-2 has provoked over 200,000 deaths/months since its emergence and only a few antiviral drugs showed clinical benefit up to this moment. Thus, chemical structures endowed with anti-SARS-CoV-2 activity are important for continuous antiviral development and natural products represent a fruitful source of substances with biological activity. In the present study, agathisflavone (AGT), a biflavonoid from Anacardium occidentale was investigated as a candidate anti-SARS-CoV-2 compound. In silico and enzymatic analysis indicated that AGT may target mainly the viral main protease (Mpro) and not the papain-like protease (PLpro) in a non-competitive way. Cell-based assays in type II pneumocytes cell lineage (Calu-3) showed that SARS-CoV-2 is more susceptible to AGT than to apigenin (APG, monomer of AGT), in a dose-dependent manner, with an EC50 of 4.23 ± 0.21 µM and CC50 of 61.3 ± 0.1 µM and with a capacity to inhibit the level of pro-inflammatory mediator tumor necrosis factor-alpha (TNF-α). These results configure AGT as an interesting chemical scaffold for the development of novel semisynthetic antivirals against SARS-CoV-2.


Assuntos
Biflavonoides , Tratamento Farmacológico da COVID-19 , Humanos , SARS-CoV-2 , Proteases 3C de Coronavírus , Biflavonoides/farmacologia , Peptídeo Hidrolases , Antivirais/química , Inibidores de Proteases/química
11.
Plant Direct ; 6(7): e416, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35844781

RESUMO

Plant PHO1 proteins play a central role in the translocation and sensing of inorganic phosphate. The maize (Zea mays ssp. mays) genome encodes two co-orthologs of the Arabidopsis PHO1 gene, designated ZmPho1;2a and ZmPho1;2b. Here, we report the characterization of the transposon footprint allele Zmpho1;2a'-m1.1, which we refer to hereafter as pho1;2a. The pho1;2a allele is a stable derivative formed by excision of an Activator transposable element from the ZmPho1;2a gene. The pho1;2a allele contains an 8-bp insertion at the point of transposon excision that disrupts the reading frame and is predicted to generate a premature translational stop. We show that the pho1;2a allele is linked to a dosage-dependent reduction in Pho1;2a transcript accumulation and a mild reduction in seedling growth. Characterization of shoot and root transcriptomes under full nutrient, low nitrogen, low phosphorus, and combined low nitrogen and low phosphorus conditions identified 1100 differentially expressed genes between wild-type plants and plants carrying the pho1;2a mutation. Of these 1100 genes, 966 were upregulated in plants carrying pho1;2a, indicating the wild-type PHO1;2a to predominantly impact negative gene regulation. Gene set enrichment analysis of the pho1;2a-misregulated genes revealed associations with phytohormone signaling and the phosphate starvation response. In roots, differential expression was broadly consistent across all nutrient conditions. In leaves, differential expression was largely specific to low phosphorus and combined low nitrogen and low phosphorus conditions. Of 276 genes upregulated in the leaves of pho1;2a mutants in the low phosphorus condition, 153 were themselves induced in wild-type plants with respect to the full nutrient condition. Our observations suggest that Pho1;2a functions in the fine-tuning of the transcriptional response to phosphate starvation through maintenance and/or sensing of plant phosphate status.

12.
Zootaxa ; 4965(1): zootaxa.4965.1.2, 2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33903494

RESUMO

Six new epigean freshwater species of the genus Caecidotea in Mexico are described. These species were collected in waterbodies located along the Trans-Mexican Volcanic Belt (TMVB) and the eastern slope of the country: Caecidotea buzwilsoni sp. nov., Caecidotea chicoensis sp. nov., Caecidotea alvarezi sp. nov., Caecidotea mintzita sp. nov., Caecidotea zacapuensis sp. nov., and one additional species Caecidotea villalobosi sp. nov. is described from the Papaloapan basin at the Atlantic Slope of Mexico. The taxonomic treatment for each species includes a detailed description, figures of characters of diagnostic importance and comments. We also provide an updated map of Caecidotea records in Mexico. This work substantially increases the number of epigean Caecidotea known to occur in Mexico to 11 species, a new total of 99 species described to North America.


Assuntos
Isópodes , Distribuição Animal , Animais , Água Doce , Isópodes/anatomia & histologia , Isópodes/classificação , México , Especificidade da Espécie
13.
Pharmaceuticals (Basel) ; 15(1)2021 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-35056078

RESUMO

Atazanavir (ATV) has already been considered as a potential repurposing drug to 2019 coronavirus disease (COVID-19); however, there are controversial reports on its mechanism of action and effectiveness as anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Through the pre-clinical chain of experiments: enzymatic, molecular docking, cell-based and in vivo assays, it is demonstrated here that both SARS-CoV-2 B.1 lineage and variant of concern gamma are susceptible to this antiretroviral. Enzymatic assays and molecular docking calculations showed that SARS-CoV-2 main protease (Mpro) was inhibited by ATV, with Morrison's inhibitory constant (Ki) 1.5-fold higher than GC376 (a positive control) dependent of the catalytic water (H2Ocat) content. ATV was a competitive inhibitor, increasing the Mpro's Michaelis-Menten (Km) more than sixfold. Cell-based assays indicated that different lineages of SARS-CoV-2 is susceptible to ATV. Using oral administration of ATV in mice to reach plasmatic exposure similar to humans, transgenic mice expression in human angiotensin converting enzyme 2 (K18-hACE2) were partially protected against lethal challenge with SARS-CoV-2 gamma. Moreover, less cell death and inflammation were observed in the lung from infected and treated mice. Our studies may contribute to a better comprehension of the Mpro/ATV interaction, which could pave the way to the development of specific inhibitors of this viral protease.

14.
Cir Cir ; 88(2): 200-205, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32116326

RESUMO

BACKGROUND: In patients with severe traumatic brain injury (TBI), there is a lack of consensus about the need and time to perform a tracheostomy. Nowadays, the decision is individualized to each case. It is considered that patients that will need a tracheostomy profit by performing it earlier. PATIENTS AND METHODS: An observational and prospective study was performed. One hundred and twenty patients in a period of 18 months between 2016 and 2018, older than 18 years, with severe TBI at the first 24 h of trauma were analyzed. Clinical, biochemical, and radiological findings at admission were measured; patients were followed up until discharge. The statistical analysis was made with Student's t-test, χ2, and prevalence risk ratio. RESULTS: Ten associated factors were grouped according to the prevalence risk ratio. The principal factors were CRASH score, IMPACT score, SAPS II score, APACHE II score, age, revised trauma score, Glasgow Coma Scale, subdural hematoma, uni or bilateral abnormal pupil reactivity, and collapse of basal cisterns. CONCLUSIONS: We conclude that there are multiple factors associated with the need for tracheostomy in adult patients with severe TBI and it is possible to predict according to our findings from admission which patients will profit by this procedure.


ANTECEDENTES: No existe aún consenso respecto de la necesidad y el tiempo de realización de traqueostomía en el paciente con trauma craneoencefálico (TCE) grave. En la actualidad, la decisión se individualiza en cada caso. Se considera que los pacientes que requieren traqueostomía tendrán mayor beneficio si se realiza de forma temprana. MÉTODO: Se llevó a cabo un estudio observacional y prospectivo, en un periodo de 18 meses entre 2016 y 2018, con 120 pacientes mayores de 18 años con diagnóstico de TCE grave, en las primeras 24 horas del trauma. Se evaluaron datos clínicos, bioquímicos y radiológicos al ingreso, y se siguió hasta el alta hospitalaria. Se analizan las variables con las prueba t de Student y ji al cuadrado, y también la tasa de riesgo de prevalencia. RESULTADOS: Los factores de riesgo asociados con la necesidad de traqueostomía en el paciente con TCE grave fueron los resultados en las escalas CRASH, IMPACT, SAPS II y APACHE II, la edad, la puntuación de la Revised Trauma Score y de la Escala de Glasgow al ingreso, la presencia y el volumen de hematoma subdural, la respuesta pupilar anormal unilateral o bilateral, y el colapso parcial o total de las cisternas basales. CONCLUSIONES: Existen numerosos factores de riesgo asociados con la necesidad de traqueostomía en los pacientes adultos con TCE grave, y es posible predecir desde el momento del ingreso qué pacientes se beneficiarán de la realización de una traqueostomía.


Assuntos
Lesões Encefálicas Traumáticas , Escala de Gravidade do Ferimento , Traqueostomia , Adulto , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Respiração Artificial , Fatores de Risco , Adulto Jovem
15.
PLoS One ; 14(6): e0218651, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31220168

RESUMO

Community marine reserves are geographical areas closed to fishing activities, implemented and enforced by the same fishermen that fish around them. Their main objective is to recover commercial stocks of fish and invertebrates. While marine reserves have proven successful in many parts of the world, their success near important marine predator colonies, such as the California sea lion (Zalophus californianus) and the Pacific harbor seal (Phoca vitulina richardii), is yet to be analyzed. In response to the concerns expressed by local fishermen about the impact of the presence of pinnipeds on their communities' marine reserves, we conducted underwater surveys around four islands in the Pacific west of the Baja California Peninsula: two without reserves (Todos Santos and San Roque); one with a recently established reserve (San Jeronimo); and, a fourth with reserves established eight years ago (Natividad). All these islands are subject to similar rates of exploitation by fishing cooperatives with exclusive rights. We estimated fish biomass and biodiversity in the seas around the islands, applying filters for potential California sea lion and harbor seal prey using known species from the literature. Generalized linear mixed models revealed that the age of the reserve has a significant positive effect on fish biomass, while the site (inside or outside of the reserve) did not, with a similar result found for the biomass of the prey of the California sea lion. Fish biodiversity was also higher around Natividad Island, while invertebrate biodiversity was higher around San Roque. These findings indicate that marine reserves increase overall fish diversity and biomass, despite the presence of top predators, even increasing the numbers of their potential prey. Community marine reserves may help to improve the resilience of marine mammals to climate-driven phenomena and maintain a healthy marine ecosystem for the benefit of both pinnipeds and fishermen.


Assuntos
Biomassa , Espécies em Perigo de Extinção , Phoca/fisiologia , Comportamento Predatório , Leões-Marinhos/fisiologia , Animais , Biodiversidade , Peixes/fisiologia , Cadeia Alimentar
16.
Zootaxa ; 4624(3): zootaxa.4624.3.6, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31716213

RESUMO

A new freshwater isopod, Caecidotea camaxtli sp. nov. (Isopoda, Asellidae) is described from Mexico. The new species can be distinguished from all other species of Caecidotea by the presence of cuticular scales on the caudal process, as well as a short and simple cannula in the apex of the endopodite of pleopod II. [Zoobank URL: urn:lsid:zoobank.org:act:082CF870-ABC3-4E25-B5F2-8CA59359C2B0].


Assuntos
Isópodes , Animais , Meio Ambiente , Água Doce , México
17.
PLoS One ; 12(7): e0182132, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28750053

RESUMO

The cotranslational folding is recognized as a very cooperative process that occurs after the nearly completion of the polypeptide sequence of a domain. Here we investigated the challenges faced by polypeptide segments of a non-vectorial ß-barrel fold. Besides the biological interest behind the SARS coronavirus non-structural protein 1 (nsp1, 117 amino acids), this study model has two structural features that motivated its use in this work: 1- its recombinant production is dependent on the temperature, with greater solubility when expressed at low temperatures. This is an indication of the cotranslational guidance to the native protein conformation. 2- Conversely, nsp1 has a six-stranded, mixed parallel/antiparallel ß-barrel with intricate long-range interactions, indicating it will need the full-length protein to fold properly. We used non-denaturing purification conditions that allowed the characterization of polypeptide chains of different lengths, mimicking the landscape of the cotranslational fold of a ß-barrel, and avoiding the major technical hindrances of working with the nascent polypeptide bound to the ribosome. Our results showed partially folded states formed as soon as the amino acids of the second ß-strand were present (55 amino acids). These partially folded states are different based on the length of polypeptide chain. The native α-helix (amino acids 24-37) was identified as a transient structure (~20-30% propensity). We identified the presence of regular secondary structure after the fourth native ß-strand is present (89 amino acids), in parallel to the collapse to a non-native 3D structure. Interestingly the polypeptide sequences of the native strands ß2, ß3 and ß4 have characteristics of α-helices. Our comprehensive analyses support the idea that incomplete polypeptide chains, such as the ones of nascent proteins much earlier than the end of the translation, adopt an abundance of specific transient folds, instead of disordered conformations.


Assuntos
Peptídeos/química , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/química , Proteínas não Estruturais Virais/química , Sequência de Aminoácidos , Dicroísmo Circular , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Biossíntese de Proteínas , Dobramento de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/química , Espalhamento a Baixo Ângulo , Difração de Raios X
19.
Rev Med Inst Mex Seguro Soc ; 55(2): 156-160, 2017.
Artigo em Espanhol | MEDLINE | ID: mdl-28296365

RESUMO

BACKGROUND: The aim of this paper is to demonstrate the clinical and radiological results of non-fusion in patients with degenerative disc disease and lumbar by placing static interspinous spacer. METHODS: A retrospective study was made in the period between January 2010 and January 2013, 130 patients were treated by placing static interspinous spacer. Patients were divided into: Group 1 (treated for diagnosis of degenerative lumbar spinal stenosis), and group 2 (those diagnosed with lumbar disc herniation). It is improving pain by visual analog scale (VAS), functional improvement based on the Oswestry scale (ODI) and radiological outcome at 6,12 and 24 months was evaluated. RESULTS: 57 female patients and 73 male were included. The most affected segments were L4 - L5 and L5 - S1. In Group 1, there was improvement in pain (VAS) at 6 months to 2 points which was maintained through 12 months and 24 months was found in 4 points. Functional improvement (ODI) at 6 and 12 months remained 13 points and 24 points and 21 months in group 2: VAS 2.7, 3, 3.5 and ODI 15 respectively at 6 and 12 months; at 24 months was found in 20 points. There were no fatal complications in 1.5% in both groups. Regarding radiological changes increased the diameter foraminal which was held at the 6, 12 and 24 month follow-up. CONCLUSIONS: The interspinous device is an effective alternative treatment for lumbar degenerative disc disease and because it was associated with significantly improved lumbar pain and return to work activity.


Introducción: el objetivo de este trabajo es demostrar los resultados clínicos y radiológicos de la no fusión en los pacientes con enfermedad degenerativa lumbar y discal mediante la colocación de espaciador interespinoso estático. Métodos: estudio retrospectivo, de enero de 2010 a enero de 2013, con 130 pacientes tratados mediante colocación de espaciador interespinoso estático. Los pacientes se dividieron en: grupo 1 (tratados por diagnóstico de canal lumbar estrecho degenerativo) y grupo 2 (pacientes con diagnóstico de hernia discal lumbar). Se evaluó la mejoría de dolor mediante escala visual análoga (VAS), mejoría funcional con base en la escala de Oswestry (ODI) y resultado radiológico a los 6, 12 y 24 meses. Resultados: se incluyeron 57 pacientes del sexo femenino y 73 masculinos. Los segmentos más afectados fueron L4 - L5 y L5 - S1. En el grupo 1 hubo mejoría del dolor a los 6 meses a 2 puntos, la cual se mantuvo hasta los 12 meses; mientras que a los 24 meses se encontró en 4 puntos. La mejoría funcional (ODI) a los 6 y 12 meses se mantuvo el 13 puntos y a los 24 meses en 21 puntos. Mientras que en el grupo 2: VAS de 2.7, 3, 3.5 respectivamente y ODI de 15 a los 6 y 12 meses; a los 24 meses se encontró en 20 puntos. Hubo complicaciones no mortales en 1.5% en ambos grupos. En cuanto a los cambios radiológicos, se demostró un aumento en el diámetro foraminal el cual se mantuvo a los 6, 12 y 24 meses de seguimiento. Conclusiones: el dispositivo interespinoso es una alternativa de tratamiento eficaz para la enfermedad degenerativa lumbar y la enfermedad discal, ya que se asoció con mejora significativa de dolor lumbar y reincorporación a actividad laboral.


Assuntos
Descompressão Cirúrgica/instrumentação , Degeneração do Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia , Procedimentos Ortopédicos/instrumentação , Próteses e Implantes , Adulto , Idoso , Descompressão Cirúrgica/métodos , Feminino , Seguimentos , Humanos , Degeneração do Disco Intervertebral/diagnóstico por imagem , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos/métodos , Medição da Dor , Radiografia , Estudos Retrospectivos , Retorno ao Trabalho , Resultado do Tratamento
20.
Appl Biochem Biotechnol ; 129-132: 727-37, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16915683

RESUMO

Biosurfactants production by a strain of Pseudomonas aeruginosa using palm oil as a sole carbon source was investigated. The experiments were carried out in 500-mL conical flasks containing 100 mL of mineral media supplemented with palm oil as the sole carbon source. The P. aeruginosa FR strain was able to reduce surface tension of three tested inorganic media. Rotation velocities from 100 to 150 rpm provided free-cell fermented media with the lowest surface tension of approx 33 mN/m. Emulsification index results of even 100% were achieved when diesel was used as oil phase. Eight surface-active compounds produced by the bacterium were identified by mass spectrometry.


Assuntos
Técnicas de Cultura de Células/métodos , Óleos de Plantas/química , Óleos de Plantas/metabolismo , Pseudomonas aeruginosa/metabolismo , Tensoativos/química , Tensoativos/metabolismo , Óleo de Palmeira , Projetos Piloto , Tensão Superficial , Tensoativos/análise
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