Scaphanocephalus spp. (Trematoda: Opisthorchiidae) in intermediate and definitive hosts of the Yucatán Peninsula, Mexico, with a re-description of Scaphanocephalus expansus.

Scaphanocephalus is a small trematode genus belonging to the family Opistorchiidae. The genus currently contains only three species associated with marine fish as intermediate hosts and fish-eating birds as definitive hosts. Here, specimens of Scaphanocephalus were collected from the Osprey, Pandion haliaetus, and the White mullet, Mugil curema in the Yucatán Peninsula, Mexico. We report for the first-time DNA sequences of adult specimens of Scaphanocephalus, particularly S. expansus, as well as a sequence of a different species sampled as metacercaria. Morphological comparisons of Scaphanocephalus expansus confirmed the identity of the adult specimens, with minor morphological variations; Scanning electron photomicrographs were included, and the species was re-described. Phylogenetic analysis based on 28S rDNA sequences showed that Scaphanocephalus is monophyletic within Opisthorchiidae and consists of three independent lineages. Sequences of adults are identical to those of S. expansus. Instead, the sequence of the metacercaria sampled from the mesentery of Mugil curema nested with specimens reported as Scaphanocephalus sp. from a labrid fish in the Mediterranean Sea, herein named it as Scaphanocephalus sp. 2.

Phylogenetic analyses based on molecular and morphological data reveal a new species of Strigea Abildgaard, 1790 (Digenea: Strigeidae) and taxonomic changes in strigeids infecting Neotropical birds of prey.

Members of the genus Strigea Abildgaard, 1790 are endoparasites of birds distributed worldwide. Adults of an undescribed species of the genus Strigea were collected from the intestines of two hawk species (Rupornis magnirostris and Accipiter coperii). Other species identified as Parastrigea macrobursa that were described in Argentina were also recovered from two hawk species (Buteogallus urubitinga and Buteogallus anthracinus) in three localities along the coasts of Mexico. Specimens of the two species were sequenced for three molecular markers, the internal transcribed spacers locus (ITS1-5.8S rDNA- ITS2) and the domains D1-D3 from the large subunit from nuclear ribosomal DNA and the cytochrome c oxidase subunit 1 from mitochondrial DNA. The newly sequenced specimens were aligned with other strigeids sequences downloaded from GenBank. Maximum likelihood and Bayesian analyses inferred with each molecular marker revealed that our specimens of Strigea sp. formed an independent lineage, which is recognized herein as a new species, Strigea magnirostris n. sp., representing the first species in Mexico and the 16th in the Neotropical region. Morphologically, the new species is distinguished from other congeneric species from the Americas by having an oral sucker with several papillae around it, well-developed pseudosuckers (118-248 µm), a tegument covered with tiny spines, a larger cone genital (193-361 × 296-637) and a larger copulatory bursa (247-531 × 468-784). Our phylogenetic analyses revealed that P. macrobursa is not closely related to other members of the genus Parastrigea and is nested within Strigea, suggesting that P. macrobursa should be transferred to Strigea to form Strigea macrobursa n. comb., expanding its distribution range from Mexico to Argentina. Finally, the analyses also revealed that the taxonomy and systematics of Strigea should be re-evaluated, combining morphological and molecular characteristics.

Molecular and morphological characterization of Andracantha gravida (Alegret, 1941) (Acanthocephala: Polymorphidae) in piscivorous birds from the Gulf of Mexico.

Adult specimens of Andracantha gravida (Alegret, 1941) were recorded from the intestines of the double-crested cormorant Nannopterum auritus (Lesson) (type host) and brown pelican Pelecanus occidentalis L. in two localities from Mexico: Celestún, Yucatan (south-eastern) and Punta Piedra, Tamaulipas (north-eastern). The specimens of A. gravida are morphologically characterized by having a pipe-shaped body without swellings, the absence of small trunk spines between the two fields of spines on the foretrunk and a cylindrical proboscis with 14-16 rows of 10-12 hooks per row. Newly generated partial sequences of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were generated from adult isolates of A. gravida from Mexico and compared with one sequence of A. gravida and with sequences of other polymorphid acanthocephalans available in GenBank. Phylogenetic analyses based on maximum likelihood and Bayesian inference methods of the cox1 dataset placed all the species of Andracantha in a single clade, with weak support. The analyses of the cox1 dataset placed Andracantha sigma Presswell, García-Varela & Smales, , as sister to the clade formed by A. gravida, Andracantha phalacrocoracis (Yamaguti, 1939), Andracantha leucocarboi Presswell, García-Varela & Smales, and an unidentified species of Andracantha from Japan. The newly generated cox1 sequences of A. gravida from piscivorous birds of Mexico formed a strongly supported clade with the published sequence of A. gravida from the double-crested cormorant from the south-eastern coast of Mexico. The intraspecific genetic divergence among isolates identified as A. gravida ranged from 0.0% to 2.2%. A cox1 haplotype network inferred with 14 sequences revealed the presence of nine haplotypes, two of which were shared between the populations of piscivorous birds from the north-eastern and south-eastern coasts of Mexico and seven of which were unique. The fixation index between the populations from north-eastern and south-eastern Mexico was low (0.06949), which suggests genetic flow. This can be explained by the migration patterns of the brown pelican and the double-crested cormorant along the coasts of the Gulf of Mexico.

Phylogenetic affinities of Forticulcitinae (Haploporidae) parasites of mullet from the Americas, with the description of three new species and notes on the genera and key species.

Members of Forticulcitinae Blasco-Costa, Balbuena, Kostadinova & Olson, 2009 include endoparasites of mullet fishes distributed worldwide. Adult specimens were collected from the intestines of white mullet (Mugil curema) and flathead grey mullet (Mugil cephalus) from five localities in the Gulf of Mexico and a single locality in Venezuela. Photogenophores were sequenced for two nuclear molecular markers, the large subunit (LSU) and second internal transcribed spacer (ITS2) of nuclear rDNA. The new sequences were aligned with other sequences downloaded from GenBank. The maximum likelihood and Bayesian inferences were deduced using the combined dataset (LSU + ITS2). The phylogenetic analyses revealed four new lineages belonging to Forticulcitinae. Three new species are described in the present study. Ekuarhuni mexicanus n. sp. can be differentiated from its congeneric species by presenting a longer hermaphroditic sac length (136-180 µm) and a wider testis (91-123 µm). Forticulcita macropharyngis n. sp. and Forticulcita venezuelensis n. sp. are the 8th and 9th species described in Forticulcita. Both species belong to the diminutive morphotype of Forticulcita. Forticulcita macropharyngis n. sp. can be morphologically distinguished from the other congeneric species by the presence of a massive and muscular pharynx (46-110 µm long, 74-106 µm wide). Forticulcita venezuelensis n. sp. is the second species of the studied genus recorded in South America and can be differentiated from congeneric species by possessing the largest testis (138-201 µm long, 83-100 µm wide). Finally, the fourth lineage corresponds to Overstreetoides Andrade-Gómez & García-Varela, 2021; however, few specimens of this lineage were collected, precluding any description of the species. In addition, a key is proposed for differentiating the genera and species of Forticulcitinae.

Revisión de la investigación sobre relaciones de pareja en países hispanohablantes (2000-2018) / Review of the literature on couple relationships in Spanish-speaking countries (2000-2018)

Resumen La relación de pareja es una dimensión central de la vida de las personas que repercute en su felicidad y bienestar. Este tema es de interés para diversas disciplinas, teniendo un amplio recorrido en investigación, y ha sido abordado desde diferentes paradigmas y perspectivas de estudio. Con el objetivo de analizar las investigaciones llevadas a cabo sobre relaciones de pareja desde el año 2000 al 2018, se revisan 83 publicaciones localizadas tras una búsqueda exhaustiva en las principales bases de datos. Los resultados apuntan a que la mayoría de las investigaciones optan por una metodología exclusivamente cuantitativa, tienden a emplear instrumentos ya validados, cuentan con muestras de hasta 250 participantes y abordan temas clásicos como la satisfacción, la sexualidad o la comunicación en pareja. La información aportada permite obtener una visión global del tema de estudio y está encaminada a poder replicar, proponer nuevas o ampliar las investigaciones ya realizadas.

Abstract Couple relationships, as the fundamental basis of family relationships, is a crucial dimension within the lives of people that also impacts on their happiness and well-being. These relationships are underpinned by mutual caring and attachment bonds, which, properly developed, entail a source of emotional and social support. This support also contributes to build the identity, improve the social competence, and, ultimately, strengthen own and family well-being. This topic is likely to arouse the interest at a social and scientific level and is addressed from several disciplines such as Psychology, Sociology, Pedagogy, or Social Work. This interest has provided this topic with a broad overview in the related research, being addressed from different paradigms and study prospects. This study is aimed at analyzing the research conducted on couple relationships from 2000 to 2018 in Spanish-speaking countries. Therefore, we present a systematic review of 83 scientific publications retrieved after an extensive search in the main databases (WOS, SCOPUS, Dialnet Plus, Redalyc, and ISOC) and the search engine Google Scholar. Specifically, the study specifies the dimensions and variables that have been the subject of study among these relationships, their objectives and methods (with particular emphasis on the instruments used), and the sample type and size the authors deemed necessary. In addition to the year of publication and the geographical delimitation, it was also included as criteria the publication format (only scientific papers) and papers with a Social Sciences content with topics not related to violence. Results suggest that most researchers follow an entirely quantitative methodology, tend to use validated instruments, have samples up to 250 participants, and address traditional topics such as satisfaction, sexuality, and communication in couples. Also, the predominant trend is to focus on a single thematic content, being lower the presence of studies addressing the interaction between two topics (e.g., satisfaction and communication), and even least common those studies that extend the dimensions analyzed to three or more. Regarding the content, the papers reviewed confirm the thinking that the couple's well-being and their satisfaction has a multicausal nature, which goes beyond the couple, since it includes the influence of the couple's social and cultural context. In this regard, specific socio-demographic characteristics such as having children, gender, and relationship duration seem to have a greater impact and arouse more interest than others. To complement this work, it is also included other topics usually related to how the couples are shaped and the satisfaction perceived, such as, for example, the fear of intimacy and anxiety, the sense of humor, the psychological well-being, and living with a positive family context. Furthermore, the publications addressed allow to locate emerging topics, such as the use of technology and its impact on the couple relationships, and also reveal the absence of studies integrating new structures of couple relationships, like polyamory. In conclusion, this review helps to get a general overview of the topic studied in order to suggest further research or expand the research already conducted. Similarly, the information provided encourages researchers to replicate the studies analyzed with different samples (location, age, sample size, etc.) and with more ambitious methodological design given that, though exceptionally, there are results which buck against the current predominant trends, and to complement this study focused on Spanish-speaking research with English, French and Portuguese publications.

The -514C>T polymorphism in the LIPC gene modifies type 2 diabetes risk through modulation of HDL-cholesterol levels in Mexicans.

PURPOSE: Both type 2 diabetes (T2D) and low levels of high-density lipoprotein cholesterol (HDL-C) are very prevalent conditions among Mexicans. Genetic variants in the LIPC gene have been associated with both conditions. This study aimed to evaluate the association of the -514C < T (rs1800588) LIPC gene polymorphism with different metabolic traits, particularly the effects of this polymorphism on HDL-C plasma levels and T2D risk. METHODS: Mediation analysis was used to assess the direct and indirect effects of the -514C>T LIPC gene variant on HDL-C levels, T2D risk, and body mass index (BMI), in 2105 Mexican mestizo participants. We also assessed the functional effect of the -514C>T LIPC variant on the promoter activity of a reporter gene in the HepG2 cell line. RESULTS: Direct effects show that the -514C>T LIPC polymorphism is significantly associated with increased HDL-C plasma levels (ß = 0.03; p < 0.001). The -514C>T variant resulted in an indirect protective effect on T2D risk through increasing HDL-C levels (ß = - 0.03; p < 0.001). Marginal direct association between -514C>T and T2D was found (ß = 0.08; p = 0.06). Variables directly influencing T2D status were European ethnicity (ß = - 7.20; p < 0.001), age (ß = 0.04; p < 0.001), gender (ß = - 0.15; p = 0.017) and HDL-C (ß = - 1.07; p < 0.001). In addition, we found that the -514C>T variant decreases the activity of LIPC promoter by 90% (p < 0.001). CONCLUSIONS: The -514C>T polymorphism was not directly associated with T2D risk. HDL-C acts as a mediator between -514C>T LIPC gene variant and T2D risk in the Mexican population.

Morphological and molecular evidence reveals a new species of Lyperosomum Looss, 1899 (Digenea: Dicrocoeliidae) from Melanerpes aurifrons (Wagler, 1829) from northern Mexico.

A new species of the genus Lyperosomum Looss, 1899, from the intestine of the golden-fronted woodpecker (Melanerpes aurifrons) from northern Mexico is described. Lyperosomum cuauhxinqui sp. n. is morphologically distinguished from other congeneric species from the Americas by a higher oral/ventral sucker ratio and its body length and width. The sequences of domains D1-D3 of the large subunit (LSU) of nuclear ribosomal DNA and cytochrome c oxidase subunit 1 (cox 1) from the mitochondrial DNA of the new species were obtained and compared with available sequences from GenBank. The genetic divergence estimated between the new species and other congeneric species ranged from 2 to 6% and 13.4 to 17.3% for LSU and cox 1, respectively. Phylogenetic analyses based on the two (LSU and cox 1) molecular markers consistently showed that L. cuauhxinqui sp. n. was nested within the genus Lyperosomum, with strong bootstrap support (100%) and Bayesian posterior probabilities (1.0). In particular, the LSU tree indicated that the sequence of the new species is closely related to sequences from Zonorchis alveyi, Zonorchis delectans and Zonorchis sp. from Central America, suggesting that these sequences should be transferred to the genus Lyperosomum. The new species represents the first record from Mexico and the fifth species identified in the Americas. Our study also revealed that the taxonomy of the genus Lyperosomum should be re-examined by combining molecular, morphological and ecological characteristics.

[Vulvar squamous cell carcinoma in young women with HPV negative]. / Carcinoma epidermoide de vulva en mujer joven con VPH negative.

BACKGROUND: The vulvar cancer is the fourth more frequent neoplasia after the endometrial, cervix and ovarian cancer. Normally, it has been related to old women of ages from 70 to 80 years old. Rarely, it has been detected cases in adult or young women. However, its incidence has been increased in the last years and in more early years. It is for this change in the incidence and its appearance in early years why a possible etiology has been looked for, opening different hypothesis that go from that related to the HPV to those that study an inflammatory chronic process as the basis for the carcinogenesis. CLINICAL CASE: In this article, it has been presented the case of a woman who is 34 years old with negative VPH that made her debut with epidermoid carcinoma of the vulva moderately different and on purpose of the case, we do a revision of the literature existent. CONCLUSIONS: Vulvar cancer diagnosed in young women as in older, but with different trends, risk factors and natural history. The case reported here escapes the theories studied so far so needed new lines of inquiry to investigate this form of presentation young woman, without HPV infection.

What is the influence of cyclooxygenase-2 on postmenopausal endometrial polyps?

BACKGROUND: The genesis of the endometrial polyp is as yet unclear. There is evidence that the polyp is related to the inflammatory process and that it interacts with the cyclooxygenase-2 (COX-2) enzyme. OBJECTIVE: To review the influence of COX-2 on the postmenopausal endometrial polyp. METHODS: A systematic review was made of the Medline, Embase, and Cochrane databases, covering the years of 2001-2014. The inclusion criteria were: experimental studies with immunohistological analysis of COX-2 in endometrial polyps; women; hysteroscopic and surgical evaluation; and studies with comparisons between the endometrial polyp and other tissues (normal endometrium, adjacent endometrium, and other uterine diseases). The exclusion criteria were: polyps in other organs; genetic polymorphisms; endometrial cancer exclusively; abnormal uterine bleeding unrelated to polyps. The search key words (taken from the Medical Subject Headings - MeSH) were endometrial polyp and cyclooxygenase-2. RESULTS: Seven of ten articles were selected. Results showed positive COX-2 expression in the glandular epithelium of the polyps, and expression was more intense when the polyp was malignant. However, there was a study which did not find any difference between polyps and the normal endometrium, and there was another which compared polyps in menacme with postmenopausal polyps. CONCLUSION: There is no consensus in the literature as to the participation of COX-2 in the development of benign and/or malignant endometrial polyps. In all of the studies, COX-2 was present in the postmenopausal polyps and with greater intensity in the malignant ones.

PKA tightly bound to human placental mitochondria participates in steroidogenesis and is not modified by cAMP.

INTRODUCTION: Protein phosphorylation plays an important role in the modulation of steroidogenesis and it depends on the activation of different signaling cascades. Previous data showed that PKA activity is related to steroidogenesis in mitochondria from syncytiotrophoblast of human placenta (HPM). PKA localization and contribution in progesterone synthesis and protein phosphorylation of HPM was assessed in this work. METHODS: Placental mitochondria and submitochondrial fractions were used. Catalytic and regulatory PKA subunits were identified by Western blot. PKA activity was determined by the incorporation of (32)P into proteins in the presence or absence of specific inhibitors. The effect of PKA activators and inhibitors on steroidogenesis and protein phosphorylation in HPM was tested by radioimmunoassay and autoradiography. RESULTS: The PKAα catalytic subunit was distributed in all the submitochondrial fractions whereas ßII regulatory subunit was the main isoform observed in both the outer and inner membranes of HPM. PKA located in the inner membrane showed the highest activity. Progesterone synthesis and mitochondrial protein phosphorylation are modified by inhibitors of PKA catalytic subunit but are neither sensitive to inhibitors of the regulatory subunit nor to activators of the holoenzyme. DISCUSSION: The lack of response in the presence of PKA activators and inhibitors of the regulatory subunit suggests that the activation of intramitochondrial PKA cannot be prevented or further activated. CONCLUSIONS: The phosphorylating activity of PKA inside HPM could be an important component of the steroidogenesis transduction cascade, probably exerting its effects by direct phosphorylation of its substrates or by modulating other kinases and phosphatases.

Mitochondrial dysfunction in the hippocampus of rats caused by chronic oxidative stress.

The aim of this study was to analyze the effects of chronic oxidative stress on mitochondrial function and its relationship to progressive neurodegeneration in the hippocampus of rats chronically exposed to ozone. Animals were exposed to 0.25 ppm ozone for 7, 15, 30, or 60 days. Each group was tested for (1) protein oxidation and, manganese superoxide dismutase (Mn-SOD), glutathione peroxidase (GPx) and succinate dehydrogenase (SDH) activity using spectrophotometric techniques, (2) oxygen consumption, (3) cytochrome c, inducible nitric oxide synthase (iNOS), peroxisome proliferator-activated receptor γ Co-activator 1α (PGC-1α), B-cell lymphoma (Bcl-2), and Bax expression using Western blotting, (4) histology using hematoxylin and eosin staining, and (5) mitochondrial structure using electron microscopy. Our results showed increased levels of carbonyl protein and Mn-SOD activity after 30 days of ozone exposure and decreased GPx activity. The SDH activity decreased from 7 to 60 days of exposure. The oxygen consumption decreased at 60 days. Western blotting showed an increase in cytochrome c at 60 days of ozone exposure and an increase in iNOS up to 60 days of ozone exposure. The expression of PGC-1α was decreased after 15, 30, and 60 days compared to the earlier time Bcl-2 was increased at 60 days compared to earlier time points, and Bax was increased after 30 and 60 days of exposure compared to earlier time points. We observed cellular damage, and mitochondrial swelling with a loss of mitochondrial cristae after 60 days of exposure. These changes suggest that low doses of ozone caused mitochondrial abnormalities that may lead to cell damage.

Effects of fetal respiratory movements on the short-term fractal properties of heart rate variability.

We evaluated the effect of fetal respiratory movements (RM) on the heart rate (HR) fractal dynamics.Abdominal ECG recordings were collected from low-middle-risk pregnant woman at rest. Mean gestational age was 34.8 ± 3.7 weeks. Ultrasound images were simultaneously acquired determining if RM were exhibited by fetuses. 13 pairs of HR series were compared. Each pair included 5 min of data from the same fetus either during the manifestation of RM or when there was no persistent indication of them. Detrended fluctuation analysis was applied to these series for obtaining the scaling exponent α1. HR series were also assessed using the conventional parameters RMSSD and HF power.The main findings of this contribution were the lack of significant changes in the scaling exponent α1 of fetal HR fluctuations as a result of RM. By contrast, HF power and RMSSD did show significant changes associated with the manifestation of fetal RM (p < 0.001 and p < 0.05, respectively). Yet the scaling exponent was the only parameter showing a significant relationship with the particular frequency of fetal RM (r s  = 0.6, p < 0.03). Given the invariability of α1 regarding the manifestation of fetal RM, we consider that the HR short-term fractal properties are convenient for assessing the cardiovascular prenatal regulation.

Analysis and characterization of cultivable extremophilic hydrolytic bacterial community in heavy-metal-contaminated soils from the Atacama Desert and their biotechnological potentials.

AIMS: To isolate and characterize the cultivable community of hydrolase producers (amylase, protease, lipase, DNase, xylanase and pullulanase) inhabiting heavy-metal-contaminated soils in extreme conditions from the Atacama Desert. METHODS AND RESULTS: A total of 25 bacterial strains showing hydrolytic activities have been selected including halotolerants, extremely halotolerants and moderate halophiles. Most hydrolase producers were assigned to the family B acillaceae, belonging to the genera Bacillus (nine strains), Halobacillus (seven strains) and Thalassobacillus (five strains) and four isolates were related to members of the families Pseudomonadaceae, Halomonadaceae and Staphylococcaceae. The selected strains were then characterized for their tolerance pattern to six heavy metals, measured as minimal inhibitory concentrations (MICs). CONCLUSIONS: The diversity found in the cultivable bacterial community analysed is more limited than that detected in other ecological studies owing to the restrictive conditions used in the screening. The dominant bacteria were Firmicutes and particularly, species related to the genus Bacillus. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is focused on the characterization of extremophilic hydrolytic bacteria, providing candidates as a source of novel enzymes with biotechnological applications.

Mitochondrial heat shock protein participates in placental steroidogenesis.

The human placenta, which does not express the StAR protein, synthesizes large amounts of progesterone. The rate-limiting step for steroidogenesis is the transport of cholesterol which is divided into two steps: 1) cholesterol flux from cytoplasm to outer membrane mitochondria, and 2) cholesterol transport from outer to inner mitochondrial membrane. The proteins mediating placental cholesterol influx have not been clearly identified. We investigated the proteins involved in the transport of cholesterol in syncytiotrophoblast mitochondria from human placenta. Two proteins, one of 30 kDa, and another of 60 kDa, were identified using anti-MLN64 antibodies. The 30 kDa protein corresponds to a fragment of MLN64, and the 60 kDa protein was identified as a heat shock protein. During steroidogenesis, mitochondria released MLN64 protein to supernatant. When this supernatant was added to fresh isolated mitochondria, progesterone synthesis increased; a similar result was obtained with the addition of the recombinant MLN64-START protein. In the presence of flurescein-5-maleimide or N-ethyl-maleimide, the mitochondrial synthesis of progesterone was inhibited in a dose-dependent fashion without changes in mitochondrial respiration. 2D-electrophoretic pattern showed that flurescein-5-maleimide- fluorescence was associated with HSP60. Both MLN64 and HSP60 were identified in mitochondrial contact sites. The results suggest that HSP60 is involved in the steroidogenic metabolism of human placenta. A tight association between MLN64 and HSP60 is suggested for cholesterol transport in the human placenta.

Short-term heart rate dynamics of pregnant women.

Aiming to detect the stage of gestation where dynamical changes of the RR fluctuations may occur, we assessed short-term fluctuations of low risk pregnant women. Ninety six, 10min ECG recordings were collected along gestation (7 to 39 weeks). Corresponding RR fluctuations series were analysed to obtain the RMSSD, α(1), α(1(mag)) and α(1(sign)) parameters. Four groups covering first, second and last trimesters of gestation were conformed. No significant changes in α(1), which was close to unit, and α(1(sign)) among gestational groups were identified. But, in accordance with previous findings, we did find a significant reduction of RMSSD along gestation, and significant short-term changes that indicate a higher degree of nonlinearity after about 26 weeks of gestation (α(1(mag))>0.5)). These results suggest that the short-term heart rate dynamics of low risk pregnant women do not become compromised during gestation, despite the increased haemodynamic demands and other ongoing adaptations. Yet the complexity of the mechanisms involved in the cardiac regulation of pregnant women does seem to increase from mid-pregnancy, possibly owing to new short-term control influences or to modifications regardless the strength of the regulatory interactions.

Short-term heart rate dynamics of women during labor.

We studied 10 minutes segments of heartbeat interval fluctuations from 18 young women in labor with normal outcome of pregnancy. Data of each studied case were classified into two distinct groups. One group involving segments where the uterine activity was observable (three or more contractions in ten minutes), and the other group of reference having segments with fewer uterine activity or not presenting contractions at all. For comparison, we also included segments collected during the last trimester of gestation prior to labor from a third group of women. Corresponding RR interval series were analyzed to estimate RR(mean), RMSSD, α(1), α(1(MAG)) and α(1(SIGN)) parameters. No significant differences among groups were identified in RMSSD, α(1) and α(1(MAG)) Nevertheless, α(1(SIGN)) did present significant differences in comparison with the last trimester results (p<0.007), revealing a subtle change in the temporal organization of maternal RR series during labor. Results of these parameters then suggest that during labor, despite preserving a concomitant non-linear influence, the maternal short-term autonomic cardiac regulation behaves with less antagonism.

Contribution of potassium in human placental steroidogenesis.

The role of K(+) on steroidogenesis in isolated mitochondria from the human placenta was explored. Cholesterol uptake and progesterone synthesis were stimulated by K(+), and by the further addition of ATP. In the presence of glibenclamide or quinine (inhibitors of the K(+) channel mito-K(ATP)), the synthesis of progesterone was improved, indicating that K(+) acts outside the mitochondria. Valinomycin, a K(+)-ionophore, inhibited mitochondrial steroidogenesis only in the absence of K(+). The mitochondrial K(+) channel in human placental mitochondria is formed by the subunit Kir 6.1 which was detected by Western blot with polyclonal antibodies. These results suggest that K(+) contributes placental mitochondrial steroidogenesis facilitating cholesterol uptake and intermembrane translocation through a mechanism non-dependent of the transport of K(+) inside the mitochondria.

Desenvolvimento de emulsões óleo de oliva/água: avaliação da estabilidade física / Development of olive oil-in-water emulsions: assessment of physical stability

Emulsões óleo de oliva/água, na presença de agentes emulsionantes não-iônicos, foram avaliadas quanto à estabilidade física. Assim, prepararam-se emulsões fazendo uso de diferentes emulsionantes, sendo um hidrofílico e o outro lipofílico, nas diferentes proporções. Às emulsões mais estáveis, adicionaram-se agentes auxiliares da emulsificação, visando otimizar a estabilidade; e estudos de estabilidade foram conduzidos, submetendo as amostras em condições e períodos diversos de armazenamento. Para caracterização da estabilidade, as amostras foram examinadas macroscopicamente e submetidas às análises de pH, centrifugação, viscosidade, potencial zeta e distribuição de tamanho de partícula. Os resultados demonstraram que as emulsões óleo de oliva/água não apresentaram alteração, ou seja mantiveram-se estáveis, quanto às propriedades organolépticas, bem como físicoquímicas, quando armazenadas à temperatura ambiente e protegidas da luz. Das emulsões obtidas, as que apresentaram maior estabilidade provêm da associação de agentes emulsionantes que resultaram em equilíbrio hidrofílico-lipofílico (EHL) equivalente a 12. As emulsões provenientes da associação de agentes emulsionantes que possuem cadeias de ácidos graxos insaturados similares ao óleo de oliva produziram estabilidade máxima, demonstrando que a similaridade estrutural entre os componentes da fase oleosa e os agentes emulsionantes é essencial para a estabilidade da emulsão.

Olive oil-in-water emulsions, developed with non-ionic emulsifiers, were assessed with regard to physical stability. Emulsions were prepared with two different emulsifiers, one of which was hydrophilic and the other lipophilic, in various proportions. To improve emulsion stability, auxiliary emulsifiers were added to the stablest emulsions and stability studies were carried out, in which the samples were stored for different periods and under various conditions. To test emulsion stability, the samples were examined macroscopically and various physicochemical properties, such as pH, centrifugation, viscosity, zeta potential and particle size distribution, were assessed. The results showed that olive oil-in-water emulsions are organoleptically and physicochemically stable, when stored at room temperature and protected from the light. Out of the emulsions developed, the most stable was based on an emulsifier blend that resulted in a hydrophilic-lipophilic balance (HLB) of 12. A blend of emulsifiers with unsaturated fatty acids of similar chain length to that of olive oil produced the stablest emulsions, showing that structural similarity between the hydrocarbon moieties of the oil phase and the surfactant is essential to successful emulsion stabilization.

Applying fractal analysis to short sets of heart rate variability data.

The aim of this study was to explore the interchangeability of fractal scaling exponents derived from short- and long-term recordings of real and synthetic data. We compared the alpha(1) exponents as obtained by detrended fluctuation analysis from RR-interval series (9 am to 6 pm) of 54 adults in normal sinus rhythm, and the alpha(1) estimated from shorted segments of these series involving only 50, 100, 200 and 300 RR intervals. Three series of synthetic data were also analysed. The principal finding of this study is the lack of individual agreement between alpha(1) derived from long and short segments of HRV data as indicated by the existence of bias and low intraclass correlation coefficient (r(i) = 0.158). The extent of variation in the estimation of alpha(1) from real data does not only appear related to segments' length, but also to different dynamics among subjects or lack of uniform scaling behaviour. However, we did find statistical agreement between the means of alpha(1) exponents from long and short segments, even for segments involving just 50 RR intervals. According to results of synthetic series, the 95% confidence interval found for the variation of alpha(1) using segments with 300 samples is [-0.1783 + 0.1828]. Caution should be taken concerning the use of short segments to obtain representative exponents of fractal RR dynamics; a circumstance not fully considered in several studies.

Intradermal hepatitis B vaccination in patients with advanced chronic renal failure: immunogenicity and follow-up.

BACKGROUND: Patients undergoing dialysis usually have a poor response to conventional hepatitis B vaccination. AIM: To observe the effects of intradermal hepatitis B (HB) vaccination in a 13-month prospective study of adult patients with end-stage renal failure. The patients were with or without previous hepatitis B vaccination, but all had antibody titres <10 mUI/mL. METHODS: Patients were allotted to two groups: previous hepatitis B virus vaccination and no previous hepatitis B virus vaccination or anti-HBs titres <10 mUI/mL. Patients in both groups received 16 i.d. injections of 0.1 mL of hepatitis B virus vaccine over an eight-week period. Patients had antibody titres assessed before vaccination, 1 month after and every 3 months for a year. Antibody titres >/=10 mUI/mL were considered protective. RESULTS: Seventy patients completed the protocol. Protective titres were elicited in 82% of each group. Age, time under dialysis, diabetes, smoking and body-mass index were not associated with seroconversion. Persistent protective titres >12 months occurred in 27 (58.7%). Adverse events were trivial. CONCLUSION: Intradermal hepatitis B virus vaccination is an alternative in end-stage renal failure.