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1.
Gac Med Mex ; 160(1): 76-85, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38753554

RESUMO

BACKGROUND: Chromosomal abnormalities are present in 50 to 60% of miscarriages and in 6 to 19% of stillbirths. Although microarrays are preferred for studying chromosomal abnormalities, many hospitals cannot offer this methodology. OBJECTIVE: To present the results of the cytogenetic analysis of 303 products of conception (POC), which included 184 miscarriages, 49 stillbirths and 17 cases of undefined age. MATERIAL AND METHODS: Karyotyping, fluorescence in situ hybridization, short tandem repeats and microarrays were used, depending on the type of loss and available sample. RESULTS: In 29 POCs we found maternal tissue and were eliminated from the analyses. Informative results were obtained in 250 (91.2 %)/274 cases; the karyotyping success rate was 80.7%; that of single nucleotide polymorphism microarrays, 94.5%; and that of fluorescence in situ hybridization and short tandem repeat, 100%. Cytogenetic abnormalities were observed in 57.6% of miscarriages and in 24.5% of stillbirths; 94% of total anomalies were numerical and 6% were submicroscopic. CONCLUSIONS: Karyotyping with simultaneous short tandem repeat study to rule out contamination of maternal cells is effective for studying miscarriages; in stillbirths, microarrays are recommended.


ANTECEDENTES: Las alteraciones cromosómicas están presentes en 50 a 60 % de los abortos espontáneos y en 6 a 19 % de los mortinatos. Aunque se prefieren los microarreglos para estudiarlos, numerosos hospitales no pueden ofrecerlos. OBJETIVO: Presentar los resultados del estudio citogenético de 303 productos de la concepción (POC), 184 se obtuvieron de abortos espontáneos, 49 fueron mortinatos y en 17 no se identificó la de edad gestacional. MATERIAL Y MÉTODOS: Se empleó cariotipo, hibridación in situ con fluorescencia, secuencias cortas repetidas en tándem y microarreglos, según el tipo de pérdida y la muestra disponible. RESULTADOS: En 29 POC se encontró tejido materno, por lo que fueron eliminados de los análisis. En 250 (91.2 %)/274 casos se obtuvieron resultados informativos; la tasa de éxito del cariotipo fue de 80.7 %; la de los microarreglos de SNP, de 94.5 %; y la de la hibridación fluorescente in situ y la repetición corta en tándem, de 100 %. Se observaron anomalías citogenéticas en 57.6 % de los abortos espontáneos y en 24.5 % de los mortinatos; 94 % de las anomalías fueron numéricas y 6 %, submicroscópicas. CONCLUSIONES: El cariotipo en conjunto con el estudio de secuencias cortas repetidas en tándem para descartar contaminación de células maternas es efectivo para estudiar abortos espontáneos; los microarreglos se recomiendan en los mortinatos.


Assuntos
Aborto Espontâneo , Aberrações Cromossômicas , Hibridização in Situ Fluorescente , Cariotipagem , Humanos , Feminino , Aborto Espontâneo/epidemiologia , Aborto Espontâneo/genética , México/epidemiologia , Gravidez , Cariotipagem/métodos , Natimorto/genética , Natimorto/epidemiologia , Adulto , Análise Citogenética/métodos , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único , Adulto Jovem
2.
Gac. méd. Méx ; 160(1): 81-91, ene.-feb. 2024. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1557807

RESUMO

Resumen Antecedentes: Las alteraciones cromosómicas están presentes en 50 a 60 % de los abortos espontáneos y en 6 a 19 % de los mortinatos. Aunque se prefieren los microarreglos para estudiarlos, numerosos hospitales no pueden ofrecerlos. Objetivo: Presentar los resultados del estudio citogenético de 303 productos de la concepción (POC), 184 se obtuvieron de abortos espontáneos, 49 fueron mortinatos y en 17 no se identificó la de edad gestacional. Material y métodos: Se empleó cariotipo, hibridación in situ con fluorescencia, secuencias cortas repetidas en tándem y microarreglos, según el tipo de pérdida y la muestra disponible. Resultados: En 29 POC se encontró tejido materno, por lo que fueron eliminados de los análisis. En 250 (91.2 %)/274 casos se obtuvieron resultados informativos; la tasa de éxito del cariotipo fue de 80.7 %; la de los microarreglos de SNP, de 94.5 %; y la de la hibridación fluorescente in situ y la repetición corta en tándem, de 100 %. Se observaron anomalías citogenéticas en 57.6 % de los abortos espontáneos y en 24.5 % de los mortinatos; 94 % de las anomalías fueron numéricas y 6 %, submicroscópicas. Conclusiones: El cariotipo en conjunto con el estudio de secuencias cortas repetidas en tándem para descartar contaminación de células maternas es efectivo para estudiar abortos espontáneos; los microarreglos se recomiendan en los mortinatos.


Abstract Background: Chromosomal abnormalities are present in 50 to 60 % of miscarriages and in 6 to 19 % of stillbirths. Although microarrays are preferred for studying chromosomal abnormalities, many hospitals cannot offer this methodology. Objective: To present the results of the cytogenetic analysis of 303 products of conception (POC), which included 184 miscarriages, 49 stillbirths and 17 cases of undefined age. Material and methods: Karyotyping, fluorescence in situ hybridization, short tandem repeats and microarrays were used, depending on the type of loss and available sample. Results: In 29 POCs we found maternal tissue and were eliminated from the analyses. Informative results were obtained in 250 (91.2 %)/274 cases; the karyotyping success rate was 80.7 %; that of single nucleotide polymorphism microarrays, 94.5 %; and that of fluorescence in situ hybridization and short tandem repeat, 100 %. Cytogenetic abnormalities were observed in 57.6 % of miscarriages and in 24.5 % of stillbirths; 94 % of total anomalies were numerical and 6 % were submicroscopic. Conclusions: Karyotyping with simultaneous short tandem repeat study to rule out contamination of maternal cells is effective for studying miscarriages; in stillbirths, microarrays are recommended.

3.
Nat Prod Res ; : 1-10, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38240473

RESUMO

Mangrove ecosystem is diverse habitat for number of medicinally important microorganisms including fungi. Scientific research from last three decade emphasises it potential in important secondary metabolites production, which have wide biological activities. The current study elaborates isolation of fungi from pneumatophore of mangrove plant Avicennia marina and investigation of ethyl acetate extract for antimicrobial, anti-inflammatory and anticancer activity. Ethyl acetate extract of the fungus displayed maximum anti-inflammatory activity with 76.39% inhibition for by protein denaturation method and 22.52% inhibition for membrane stabilisation method with respect to standard ibuprofen. Further, the anticancer activity of Aspergillus stellatus LM-03 exhibited against MCF-7 of breast cancer cell with an IC50 value of 33.24 µg/ml. HPLC and UPLC-ESI-QTOF analysis displayed nine compound mainly alternariol monomethyl ether and methyl jasmonate, which are highly anticancer activity and moderate anti-inflammatory activity with other compounds as angelic anhydride, DL-3-(4-Hydroxyphenyl)lactic acid, 8,9-epoxyl-3-isobutyryloxy-10-(2-methylbutanoyl)thymol, 5-(6-methyl-7-oxooctyl) furan-2(5H)-one and phenyl-butyryl-glutamine with an unidentified compounds. The results of the current study indicate that it may be worthwhile to investigate Aspergillus stellatus LM-03 extract for promising bioactive metabolites with potential for medicinal use.

4.
Environ Pollut ; 341: 122885, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37951525

RESUMO

The abundance of fecal-indicating bacteria in water bodies are said to be influenced by environmental conditions. The effect of environmental parameters on the changing microbial population plays an important role in coastal water quality assessment. It's crucial to comprehend these patterns in order to support management initiatives for pollution control. There are studies on faecal bacteria contamination of surface water and how environmental conditions affect it, however majority of them are based on large river basins and temperate regions of developed countries. In this paper, we study the different physicochemical and physical factors of the five recreational beaches in Mumbai, India and examine how these environmental factors affect the levels of faecal indicating bacteria, namely, coliforms in the region. A relatively high number of coliform was identified from the water and sediment samples of Marve Beach (>1600 MP N/100 ml or g), followed by Erangal Beach and Danapani Beach (∼150-350 MP N/100 ml or g), exceeding the normal standard limits of <100 MP N/100 ml set by the Central Pollution Control Board (CPCB) of India. Of the physiochemical parameters examined, BOD showed to have a strong positive correlation with the coliform bacteria. The nutrients and heavy metal concentrations did not show any major effect on the microbial population. The MIKE CMAP predicted tide, MIKE3 Flow Model FM simulated coastal current, ERA5 hourly wind, as well as SWAN model simulated nearshore wave together considerably exhibit alliance of microbial behavior in the beaches with ambient physical processes. This study reveals that Mumbai's coastal water contain significant concentrations of faecal bacteria, which, if not monitored regularly could have future consequences on the recreational activities of the region, thereby on public health. This assessment might help in simulation of water quality prediction, and for optimizing the coastal zone management and development across recreational beaches.


Assuntos
Praias , Microbiologia da Água , Bactérias , Qualidade da Água , Bactérias Gram-Negativas , Fezes/microbiologia , Índia , Monitoramento Ambiental
5.
Mol Plant ; 17(2): 277-296, 2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-38155570

RESUMO

The hexaploid sweetpotato (Ipomoea batatas) is one of the most important root crops worldwide. However, its genetic origin remains controversial, and its domestication history remains unknown. In this study, we used a range of genetic evidence and a newly developed haplotype-based phylogenetic analysis to identify two probable progenitors of sweetpotato. The diploid progenitor was likely closely related to Ipomoea aequatoriensis and contributed the B1 subgenome, IbT-DNA2, and the lineage 1 type of chloroplast genome to sweetpotato. The tetraploid progenitor of sweetpotato was most likely I. batatas 4x, which donated the B2 subgenome, IbT-DNA1, and the lineage 2 type of chloroplast genome. Sweetpotato most likely originated from reciprocal crosses between the diploid and tetraploid progenitors, followed by a subsequent whole-genome duplication. In addition, we detected biased gene exchanges between the subgenomes; the rate of B1 to B2 subgenome conversions was nearly three times higher than that of B2 to B1 subgenome conversions. Our analyses revealed that genes involved in storage root formation, maintenance of genome stability, biotic resistance, sugar transport, and potassium uptake were selected during the speciation and domestication of sweetpotato. This study sheds light on the evolution of sweetpotato and paves the way for improvement of this crop.


Assuntos
Genoma de Planta , Metagenômica , Filogenia , Tetraploidia , Haplótipos , Domesticação
6.
BMC Psychiatry ; 23(1): 30, 2023 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-36635641

RESUMO

BACKGROUND: Mental health challenges are on the rise worldwide. In Iceland, little is known about the sociodemographic factors associated with poor mental health. This study aimed to investigate symptoms of depression, anxiety, stress, and psychiatric medication for mental disorders in a nationally representative sample in Iceland and to explore its associations with sociodemographic factors. METHODS: This Icelandic cross-sectional study 'Health and Wellbeing of Icelanders' was conducted in 2017 and included 9,887 randomly chosen adults. Participants' depression, anxiety, and stress levels were measured with the Depression Anxiety and Stress scale-21(DASS-21) and the association with sociodemographic factors and prescribed psychiatric medication was assessed in a multinominal logistic regression analysis. RESULTS: The youngest age group (18 to 29 years old) had the poorest mental health. Males had a higher risk of medium and high depression scores than females, RRR 1.23 (95% CI 1.06-1.44) and RRR 1.71 (95% CI 1.25-2.33) when adjusted for sociodemographic factors (age, sex, education, marital status, financial status, living area, employment) and use of psychiatric medication. Participants with the most considerable financial difficulties had the highest risk of high scores on depression RRR 11.19 (95% CI 5.8-21.57), anxiety RRR 12.35 (95% CI 5.62-27.14) and stress RRR 11.55 (95% CI 4.75-28.04) when compared to those that do not. CONCLUSIONS: The youngest participants and those with the most extensive financial difficulties had the highest depression, anxiety, and stress scores. Males scored higher than females on depression. There was a trend towards worse mental health with lower sociodemographic status. Higher education, living with someone, and financial security were associated with better mental health. These results implicate the importance of government actions to counteract social inequalities in the Icelandic nation.


Assuntos
Depressão , Saúde Mental , Masculino , Adulto , Feminino , Humanos , Adolescente , Adulto Jovem , Islândia/epidemiologia , Depressão/diagnóstico , Estudos Transversais , Ansiedade/diagnóstico
7.
Sci Total Environ ; 858(Pt 3): 160071, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36356762

RESUMO

Anthropogenic litter is a ubiquitous stressor in the global ocean, and poses ominous threats to oceanic biodiversity and ecosystem functioning. At the terrestrial-ocean interface, tropical mangrove forests are subject to substantial exposure to mismanaged litter from inland and marine sources. While the effects of litter in different marine ecosystems are well-documented, research on the ecological consequences of litter pollution on mangroves remain nascent stage. Here, we investigated anthropogenic litter concentration, composition, probable sources, and impact on coastal mangroves along the Central West coast of India. The mean concentration of trapped litter was measured 8.5 ± 1.9 items/m2 (ranged 1.4 ̶ 26.9 items/m2), and 10.6 ± 0.5 items/tree (ranged 0 ̶ 85 items/tree) on the mangrove floor and mangrove canopy, respectively. Plastic dominated 83.02 % of all litter deposited on the mangrove forest floor and 93.4 % of all entangled litter on mangrove canopy. Most litter comprised single-use plastic products across all surveyed locations. Mangrove floor cleanliness was assessed using several indices, such as Clean Coast Index, General Index, Hazardous Items Index, and Pollution Load Index, reiterating an inferior cleanliness status. The pollution load index indicates "Hazard level I" plastic pollution risk across the mangroves. Litter concentration differed markedly across all sites. However, a significantly higher concentration of stranded litter was detected in the densely populated urban agglomeration and rural areas with inadequate solid waste management. Probable sources of litter indicate land-based (local) and sea-originated (fishing). Supportive information on the transport and accumulation of marine litter is examined based on the National Centers for Environmental Prediction (NCEP) Climate Forecast System (CFS) model version 2 reanalysis of surface wind and current pattern across the Arabian Sea followed by MIKE simulated tide-induced coastal current. Mangrove pneumatophores and branches were found to be damaged by entangled plastics. Hence, determining litter quantum and their probable input source is pivotal in mitigating anthropogenic litter impact on mangrove ecosystems and fostering mangrove conservation. Overall, results envisage that stringent enforcement, implementation of an integrated solid waste management framework, and general behavioral change of the public are crucial to mitigate litter/plastic pollution.


Assuntos
Ecossistema , Índia
8.
JMIR Form Res ; 5(10): e28519, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34596569

RESUMO

BACKGROUND: The contact tracing and subsequent quarantining of health care workers (HCWs) are essential to minimizing the further transmission of SARS-CoV-2 infection and mitigating the shortage of HCWs during the COVID-19 pandemic situation. OBJECTIVE: This study aimed to assess the yield of contact tracing for COVID-19 cases and the risk stratification of HCWs who are exposed to these cases. METHODS: This was an analysis of routine data that were collected for the contact tracing of COVID-19 cases at the All India Institute of Medical Sciences, Bhubaneswar, in Odisha, India. Data from March 19 to August 31, 2020, were considered for this study. COVID-19 cases were admitted patients, outpatients, or HCWs in the hospital. HCWs who were exposed to COVID-19 cases were categorized, per the risk stratification guidelines, as high-risk contacts or low-risk contacts. RESULTS: During contact tracing, 3411 HCWs were identified as those who were exposed to 360 COVID-19 cases. Of these 360 cases, 269 (74.7%) were either admitted patients or outpatients, and 91 (25.3%) were HCWs. After the risk stratification of the 3411 HCWs, 890 (26.1%) were categorized as high-risk contacts, and 2521 (73.9%) were categorized as low-risk contacts. The COVID-19 test positivity rates of high-risk contacts and low-risk contacts were 3.8% (34/890) and 1.9% (48/2521), respectively. The average number of high-risk contacts was significantly higher when the COVID-19 case was an admitted patient (number of contacts: mean 6.6) rather than when the COVID-19 case was an HCW (number of contacts: mean 4.0) or outpatient (number of contacts: mean 0.2; P=.009). Similarly, the average number of high-risk contacts was higher when the COVID-19 case was admitted in a non-COVID-19 area (number of contacts: mean 15.8) rather than when such cases were admitted in a COVID-19 area (number of contacts: mean 0.27; P<.001). There was a significant decline in the mean number of high-risk contacts over the study period (P=.003). CONCLUSIONS: Contact tracing and risk stratification were effective and helped to reduce the number of HCWs requiring quarantine. There was also a decline in the number of high-risk contacts during the study period. This indicates the role of the implementation of hospital-based, COVID-19-related infection control strategies. The contact tracing and risk stratification approaches that were designed in this study can also be implemented in other health care settings.

9.
BMC Public Health ; 19(1): 1413, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664974

RESUMO

BACKGROUND: Adolescence is crucial period for laying the foundations for healthy development and mental well-being. The increasing prevalence of mental disorders amongst adolescents makes promotion of mental well-being and prevention interventions at schools important. UPRIGHT (Universal Preventive Resilience Intervention Globally implemented in schools to improve and promote mental Health for Teenagers) is designed as a whole school approach (school community, students and families) to promote a culture of mental well-being and prevent mental disorders by enhancing resilience capacities. The present article aims at describing the rationale, conceptual framework, as well as methodology of implementation and evaluation of the UPRIGHT intervention. METHODS: UPRIGHT project is a research and innovation project funded by the European Union's Horizon 2020 Research and Innovation programme under grant agreement No. 754919 (Duration: 48 months). The theoretical framework has been developed by an innovative and multidisciplinary approach using a co-creation process inside the UPRIGHT Consortium (involving seven institutions from Spain, Italy, Poland, Norway, Denmark, and Iceland). Resulted is the UPRIGHT programme with 18 skills related to 4 components: Mindfulness, Coping, Efficacy and Social and Emotional Learning. Among the five Pan-European regions, 34 schools have been currently involved (17 control; 17 intervention) and around 6000 adolescents and their families are foreseen to participate along a 3-year period of evaluation. Effectiveness of the intervention will be evaluated as a randomized controlled trial including quantitative and qualitative analysis in the five Pan-European regions representative of the cultural and socioeconomic diversity. The cost-effectiveness assessment will be performed by simulation modelling methods. DISCUSSION: We expect a short- to medium-term improvement of mental well-being in adolescents by enhancing resilience capacities. The study may provide robust evidence on intrapersonal, familiar and social environmental resilience factors promoting positive mental well-being. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03951376 . Registered 15 May 2019.


Assuntos
Saúde Mental , Resiliência Psicológica , Serviços de Saúde Escolar , Estudantes/psicologia , Adolescente , Criança , Europa (Continente) , Humanos , Projetos de Pesquisa , Estudantes/estatística & dados numéricos
10.
Sci Rep ; 9(1): 12584, 2019 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-31467320

RESUMO

The discovery of the insertion of IbT-DNA1 and IbT-DNA2 into the cultivated (hexaploid) sweetpotato [Ipomoea batatas (L.) Lam.] genome constitutes a clear example of an ancient event of Horizontal Gene Transfer (HGT). However, it remains unknown whether the acquisition of both IbT-DNAs by the cultivated sweetpotato occurred before or after its speciation. Therefore, this study aims to evaluate the presence of IbT-DNAs in the genomes of sweetpotato's wild relatives belonging to the taxonomic group series Batatas. Both IbT-DNA1 and IbT-DNA2 were found in tetraploid I. batatas (L.) Lam. and had highly similar sequences and at the same locus to those found in the cultivated sweetpotato. Moreover, IbT-DNA1 was also found in I. cordatotriloba and I. tenuissima while IbT-DNA2 was detected in I. trifida. This demonstrates that genome integrated IbT-DNAs are not restricted to the cultivated sweetpotato but are also present in tetraploid I. batatas and other related species.


Assuntos
Agrobacterium/genética , DNA Bacteriano/genética , Transferência Genética Horizontal , Genoma de Planta/genética , Ipomoea batatas/genética , Poliploidia , Evolução Molecular , Filogenia
11.
Front Plant Sci ; 8: 2015, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29225610

RESUMO

Horizontal gene transfer (HGT) can be defined as the acquisition of genetic material from another organism without being its offspring. HGT is common in the microbial world including archaea and bacteria, where HGT mechanisms are widely understood and recognized as an important force in evolution. In eukaryotes, HGT now appears to occur more frequently than originally thought. Many studies are currently detecting novel HGT events among distinct lineages using next-generation sequencing. Most examples to date include gene transfers from bacterial donors to recipient organisms including fungi, plants, and animals. In plants, one well-studied example of HGT is the transfer of the tumor-inducing genes (T-DNAs) from some Agrobacterium species into their host plant genomes. Evidence of T-DNAs from Agrobacterium spp. into plant genomes, and their subsequent maintenance in the germline, has been reported in Nicotiana, Linaria and, more recently, in Ipomoea species. The transferred genes do not produce the usual disease phenotype, and appear to have a role in evolution of these plants. In this paper, we review previous reported cases of HGT from Agrobacterium, including the transfer of T-DNA regions from Agrobacterium spp. to the sweetpotato [Ipomoea batatas (L.) Lam.] genome which is, to date, the sole documented example of a naturally-occurring incidence of HGT from Agrobacterium to a domesticated crop plant. We also discuss the possible evolutionary impact of T-DNA acquisition on plants.

12.
Probiotics Antimicrob Proteins ; 6(3-4): 141-56, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25117002

RESUMO

This study evaluated the probiotic properties (stability at different pH values and bile salt concentration, auto-aggregation and co-aggregation, survival in the presence of antibiotics and commercial drugs, study of ß-galactosidase production, evaluation of the presence of genes encoding MapA and Mub adhesion proteins and EF-Tu elongation factor, and the presence of genes encoding virulence factor) of four LAB strains (Lactobacillus casei SJRP35, Leuconostoc citreum SJRP44, Lactobacillus delbrueckii subsp. bulgaricus SJRP57 and Leuconostoc mesenteroides subsp. mesenteroides SJRP58) which produced antimicrobial substances (antimicrobial peptides). The strains survived the simulated GIT modeled in MRS broth, whole and skim milk. In addition, auto-aggregation and the cell surface hydrophobicity of all strains were high, and various degrees of co-aggregation were observed with indicator strains. All strains presented low resistance to several antibiotics and survived in the presence of commercial drugs. Only the strain SJRP44 did not produce the ß-galactosidase enzyme. Moreover, the strain SJRP57 did not show the presence of any genes encoding virulence factors; however, the strain SJRP35 presented vancomycin resistance and adhesion of collagen genes, the strain SJRP44 harbored the ornithine decarboxylase gene and the strain SJRP58 generated positive results for aggregation substance and histidine decarboxylase genes. In conclusion, the strain SJRP57 was considered the best candidate as probiotic cultures for further in vivo studies and functional food products development.


Assuntos
Queijo/microbiologia , Lactobacillaceae/metabolismo , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bovinos , Fermentação , Lactobacillaceae/efeitos dos fármacos , Lactobacillaceae/genética , Lactobacillaceae/crescimento & desenvolvimento , Leite/microbiologia , Probióticos/química , Probióticos/metabolismo
13.
Carbohydr Polym ; 92(2): 1767-75, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23399218

RESUMO

PLA biocomposites were prepared using three corn cob fractions and a wood fiber as reference. The composites were characterized by tensile testing, scanning electron microscopy (SEM) and polarization optical microscopy (POM). Micromechanical deformation processes were followed by acoustic emission measurements. The different strength of the components was proved by direct measurements. Two consecutive micromechanical deformation processes were detected in composites containing the heavy fraction of corncob, which were assigned to the fracture of soft and hard particles, respectively. The fracture of soft particles does not result in the failure of the composites that is initiated either by the fracture of hard particles or by matrix cracking. Very large particles debond easily from the matrix resulting in catastrophic failure at very low stresses. At sufficiently large shear stresses large particles break easily during compounding, thus reinforcement depending on interfacial adhesion was practically the same in all composites irrespectively of initial fiber characteristics.


Assuntos
Ácido Láctico/química , Lignina/química , Polímeros/química , Poliésteres , Estresse Mecânico , Relação Estrutura-Atividade , Resistência à Tração , Madeira/química
14.
Biol Res ; 44(4): 329-37, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22446595

RESUMO

In their journey through the oviduct some subpopulations of sperm are preserved in a reservoir, while others are negatively selected. Sperm binding glycoprotein (SBG) is a pig oviductal epithelial cell glycoprotein that produces, under capacitating conditions, acrosome alteration, p97 tyrosine-phosphorylation and reduction of the motility of sperm. In this paper, we show that SBG is accessible at the extracellular surface of the oviductal epithelial cells, supporting a sperm interaction biological role in situ. We analyze the possible dependence of the tyrosine-phosphorylation of p97 on the PKA mechanism, finding that apparently it is not PKA dependent. Also, after SBG treatment the phosphorylated proteins locate mainly at the detached periacrosomal region and at the tail of sperm; the latter may be related to SBG's motility reduction effect. The study of the time course effect of SBG on sperm as detected by chlortetracycline (CTC) staining and of its binding to sperm by immunodetection in conjunction with CTC, shows results in agreement with the hypothesis that this glycoprotein is involved in the alteration of acrosomes in a specific sperm subpopulation. The results suggest that SBG may be part of a mechanism for negative selection of sperm.


Assuntos
Oviductos/metabolismo , Proteínas de Plasma Seminal/fisiologia , Capacitação Espermática/fisiologia , Espermatozoides/fisiologia , Animais , Feminino , Masculino , Interações Espermatozoide-Óvulo/fisiologia , Sus scrofa
15.
Biol. Res ; 44(4): 329-337, 2011. ilus
Artigo em Inglês | LILACS | ID: lil-626731

RESUMO

In their journey through the oviduct some subpopulations of sperm are preserved in a reservoir, while others are negatively selected. Sperm binding glycoprotein (SBG) is a pig oviductal epithelial cell glycoprotein that produces, under capacitating conditions, acrosome alteration, p97 tyrosine-phosphorylation and reduction of the motility of sperm. In this paper, we show that SBG is accessible at the extracellular surface of the oviductal epithelial cells, supporting a sperm interaction biological role in situ. We analyze the possible dependence of the tyrosine-phosphorylation of p97 on the PKA mechanism, finding that apparently it is not PKA dependent. Also, after SBG treatment the phosphorylated proteins locate mainly at the detached periacrosomal region and at the tail of sperm; the latter may be related to SBG's motility reduction effect. The study of the time course effect of SBG on sperm as detected by chlortetracycline (CTC) staining and of its binding to sperm by immunodetection in conjunction with CTC, shows results in agreement with the hypothesis that this glycoprotein is involved in the alteration of acrosomes in a specific sperm subpopulation. The results suggest that SBG may be part of a mechanism for negative selection of sperm.


Assuntos
Animais , Feminino , Masculino , Oviductos/metabolismo , Proteínas de Plasma Seminal/fisiologia , Capacitação Espermática/fisiologia , Espermatozoides/fisiologia , Sus scrofa , Interações Espermatozoide-Óvulo/fisiologia
16.
Anim Reprod Sci ; 116(3-4): 308-17, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19329263

RESUMO

The presence, topology and dynamics of heparin-binding proteins (HBP) on boar sperm were evaluated. HBP distribution was analyzed by subcellular parting, using biotinylated heparin followed by colorimetric detection. HBP were detected as peripherical and integral periacrosomal membrane proteins. Indirect fluorescence microscopy of sperm incubated with biotinylated heparin was used to evidence heparin binding on sperm at different physiological stages. Two different fluorescent patterns (A and B) were found, which probably correspond to non-capacitated and capacitated sperm as assessed by the ability to undergo acrosome reaction with calcium ionophore A23187 and by the increase of p32 phosphorylated protein. In A pattern, corresponding to untreated sperm, fluorescence located mostly on the post-acrosomal region; in B pattern, corresponding to incubated sperm, on the acrosomal region. Upon incubation under capacitating conditions (TALP), sperm having the B pattern was augmented compared with non-incubated sperm (p<0.001). Differences in the HBP patterns (p<0.0001) were observed in sperm incubated under non-capacitating conditions in relation to sperm incubated in TALP, indicating that the modification of HBP patterns is probably related to capacitation. No difference was observed when untreated sperm were permeabilized prior to staining, suggesting that HBP are present on the sperm surface. The effect of heparin on capacitation dependent protein tyrosine phosphorylation was also analyzed, finding a decrease in p32 phosphorylation in the presence of heparin. This suggests that the capacitation enhancement mediated by this glycosaminoglycan involves an alternative intracellular pathway. The finding that heparin binds to sperm differently according to its physiological state, is a new evidence of the remodelling of sperm membrane surface upon capacitation and may provide a useful and relatively simple method to evaluate in vitro modification of boar sperm physiological state.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Proteínas Sanguíneas/metabolismo , Proteínas de Transporte/metabolismo , Heparina/farmacocinética , Espermatozoides/metabolismo , Sus scrofa/metabolismo , Reação Acrossômica/efeitos dos fármacos , Reação Acrossômica/fisiologia , Algoritmos , Animais , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Proteínas Sanguíneas/isolamento & purificação , Proteínas de Transporte/isolamento & purificação , Extratos Celulares/química , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Masculino , Fosforilação/efeitos dos fármacos , Ligação Proteica , Proteínas Tirosina Quinases/metabolismo , Capacitação Espermática/efeitos dos fármacos , Capacitação Espermática/fisiologia , Espermatozoides/química , Espermatozoides/efeitos dos fármacos , Tirosina/metabolismo
17.
J Chem Theory Comput ; 3(4): 1284-94, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26633202

RESUMO

The well-known N lone-pair orientation effect on (1)JCC spin-spin coupling constants (SSCCs) in oximes and their derivatives was used to study how negative hyperconjugative interactions of type LP1(O) → σ*CC depend on ortho interactions involving the OH group. This study demanded the following analyses: (i) a qualitative estimation of how (1)JCC SSCCs are affected by hyperconjugative interactions, (ii) a study of similar stereochemical effects to those in oximes, but in (1)JC1C2 and (1)JC1C6in a series of 2-substituted phenols, and (iii) a quantitative estimation, with the natural bond order approach, of some key electron delocalization interactions. A few unexpected results are quoted. LP1(O) → σ*CC interactions are affected by proximity interactions as follows: (a) they are enhanced by hydrogen bonds transferring charge into the (O-H)* antibonding orbital; (b) they are enhanced by proximity interactions of type LP1(O)···H-C; (c) they are inhibited by interactions of type LP(O1)···H-O. Consequences of these observations are discussed.

18.
Biol Res ; 39(4): 631-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17657344

RESUMO

Chlortetracycline (CTC) fluorescent pattern, the ability to undergo acrosome reaction (AR) upon exposure to 10 microM calcium ionophore A23187 and vitality estimation were used to investigate the effect of the sulfated glycosaminoglycan heparin on the in vitro capacitation of porcine spermatozoa. Sperm incubation in capacitating medium (CM) supplemented with 10 mM heparin for up to 120 min, showed an increase in the number of capacitated sperm (B pattern) and acrosome reacted sperm (AR pattern), without affecting their viability. In this condition, spermatozoa were incubated in CM depleted of albumin, calcium, bicarbonate or combinations, in the presence of heparin. In either calcium or bicarbonate-free media, capacitation was only basal and did not show variations in the presence of heparin. In absence of albumin the presence of calcium and bicarbonate stimulated capacitation, which was further increased by the addition of heparin. These results suggest that heparin enhances in vitro capacitation of porcine sperm only under capacitating conditions. Additionally, when sperm were incubated with 100 microg/ml biotinylated heparin in the presence or absence of unlabeled heparin, we observed that heparin binding sites were located mostly on the acrosomal region of boar sperm in an specific and saturable manner. The in vitro effect of heparin described in this work indicates that sulfated glycosaminoglycans, which are normally present in the female reproductive tract, might play an important role in the fertilization process in porcines.


Assuntos
Heparina/farmacologia , Capacitação Espermática/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Animais , Clortetraciclina , Corantes , Masculino , Microscopia de Fluorescência , Espermatozoides/fisiologia , Sus scrofa
19.
Biol. Res ; 39(4): 631-639, 2006. ilus, graf
Artigo em Inglês | LILACS | ID: lil-456598

RESUMO

Chlortetracycline (CTC) fluorescent pattern, the ability to undergo acrosome reaction (AR) upon exposure to 10 µM calcium ionophore A23187 and vitality estimation were used to investigate the effect of the sulfated glycosaminoglycan heparin on the in vitro capacitation of porcine spermatozoa. Sperm incubation in capacitating medium (CM) supplemented with 10 mM heparin for up to 120 min, showed an increase in the number of capacitated sperm (B pattern) and acrosome reacted sperm (AR pattern), without affecting their viability. In this condition, spermatozoa were incubated in CM depleted of albumin, calcium, bicarbonate or combinations, in the presence of heparin. In either calcium or bicarbonate-free media, capacitation was only basal and did not show variations in the presence of heparin. In absence of albumin the presence of calcium and bicarbonate stimulated capacitation, which was further increased by the addition of heparin. These results suggest that heparin enhances in vitro capacitation of porcine sperm only under capacitating conditions. Additionally, when sperm were incubated with 100 µg/ml biotinylated heparin in the presence or absence of unlabeled heparin, we observed that heparin binding sites were located mostly on the acrosomal region of boar sperm in an specific and saturable manner. The in vitro effect of heparin described in this work indicates that sulfated glycosaminoglycans, which are normally present in the female reproductive tract, might play an important role in the fertilization process in porcines.


Assuntos
Animais , Masculino , Heparina/farmacologia , Capacitação Espermática/efeitos dos fármacos , Espermatozoides/fisiologia , Clortetraciclina , Corantes , Microscopia de Fluorescência , Sus scrofa
20.
Int J Pharm ; 301(1-2): 33-40, 2005 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-16040214

RESUMO

The stability and thermal behaviour of two anhydrate phases and a new mixed water:DMSO solvate of Olanzapine (2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno-[2,3-b][1,5]benzodiazepine) are studied by different methods: differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and Raman scattering (RS). Single crystal structural data for the latter phase are presented, confirming the presence of the (Olanzapine)(2) dimer as the structural building unit of all known phases of the drug, either anhydrate or solvated. An apparent interconversion between both solid state forms is shown to be an artifact and explained in terms of a melting-recrystallization process.


Assuntos
Antipsicóticos/química , Benzodiazepinas/química , Varredura Diferencial de Calorimetria , Fenômenos Químicos , Físico-Química , Cristalização , Dimetil Sulfóxido , Estabilidade de Medicamentos , Temperatura Alta , Modelos Moleculares , Olanzapina , Solventes , Análise Espectral Raman , Termogravimetria , Difração de Raios X
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