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BACKGROUND: Food allergy (FA) is associated with poor health-related quality of life and high levels of psychological distress. Psychological support is extremely important but not always available. As part of the Global Access to Psychological Services for Food Allergy (GAPS) study, we aimed to assess psychological distress and service use among adults, caregivers and children with FA in a global survey. METHODS: Participants (n = 1329 adults with FA; n = 1907 caregivers of children with FA) from >20 countries were recruited through patient organisations, social media advertisements and online survey panels to complete an online survey. Surveys were available in six languages. RESULTS: A total of 67.7% of adults and 77.2% of caregivers reported direct experience, and 51.6% of caregivers said their child had experienced FA-related psychological distress. The most commonly reported issue was anxiety about having an allergic reaction. Less than 20% had been assessed for FA-related psychological distress. There were significant differences across countries for levels of distress, screening for distress, seeing a mental health professional and being diagnosed with a FA-related mental health disorder (all p < .001). The United Kingdom, Australia and Brazil had the highest number of participants reporting distress. The most commonly reported barrier to seeing a mental health professional was cost. CONCLUSIONS: FA-related distress is common across countries, but with substantial country-to-country variability. Allergy providers are encouraged to routinely assess families for psychological distress and provide access to appropriate mental health resources. Development and implementation of evidence-based, patient-informed accessible, affordable FA interventions in multiple languages is urgently needed.
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X-ray phase contrast imaging (XPCI) methods give access to contrast mechanisms that are based on the refractive properties of matter on top of the absorption coefficient in conventional x-ray imaging. Ultra small angle x-ray scattering (USAXS) is a phase contrast mechanism that arises due to multiple refraction events caused by physical features of a scale below the physical resolution of the used imaging system. USAXS contrast can therefore give insight into subresolution structural information, which is an ongoing research topic in the vast field of different XPCI techniques. In this study, we quantitatively compare the USAXS signal retrieved by the beam tracking XPCI technique with the gold standard of the analyzer based imaging XPCI technique using a synchrotron x-ray source. We find that, provided certain conditions are met, the two methods measure the same quantity.
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Delayed cord clamping (DCC) and umbilical cord milking (CM) have many benefits. However, a previous study done in Zambia showed that it was not a common practice among midwives. This study investigated possible barriers to DCC and CM, at the University Teaching Hospital in Lusaka. This was a qualitative study. A convenience sample was chosen, and snowball sampling was used. The midwives were interviewed using semi-structured interviews. Burnard's method of thematic content analysis was used. Through 14 interviews it became clear that the midwives were aware of DCC and used it whenever possible. The participants reported that the main barriers were the high workload and a variation in knowledge. A lack of facilities, such as heaters and resuscitation equipment in the delivery room also led to earlier cord clamping. The midwives were motivated to continue improving the routines. They expressed a need for more training as well as equipment and resources to facilitate DCC.
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BACKGROUND: Positive self-care behaviours are more likely in young people who engage with allergy support groups, but reasons for this association are not well understood. OBJECTIVES: This study explored how and why young people engage with allergy support groups to identify what activities and resources are beneficial. METHODS: In-depth, semistructured interviews were conducted with young people aged 12-21 years who reported engaging with allergy support groups (in person or online). Interviews were audiotaped, transcribed verbatim and analysed using thematic content analysis. RESULTS: The 21 participants had a range of allergies; initially, most joined support groups on suggestion of their parent/carer although older participants sought groups independently. Feeling included and sharing experiences with people with similar problems/challenges were highly valued. Through membership, young people reported improved self-esteem and confidence in both managing their allergies and lives generally. Information, such as allergy alerts and hard-hitting video campaigns, were reported to positively influence adherence to self-care behaviours such as carrying medication. Participants wanted greater availability of allergy support groups, and higher profiles in health care and educational settings, as well as through social media. CONCLUSIONS AND CLINICAL RELEVANCE: Participants valued the psychological and practical support of networking with others with allergies, and described how membership improved their confidence. This study also provides insight into the ways support groups improve young people's adherence to medical advice and positive self-care behaviours; participants responded well to hard-hitting video campaigns which appeared to emphasize the severity and susceptibility of anaphylaxis. Participants identified the need for more active promotion of support groups amongst young people and their clinicians, as well as making them available in more localities.
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Hipersensibilidade/epidemiologia , Grupos de Autoajuda , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Motivação , Vigilância em Saúde Pública , Pesquisa Qualitativa , Autoimagem , Adulto JovemRESUMO
Syncytial nuclear aggregates (SNAs), clusters of nuclei in the syncytiotrophoblast of the human placenta, are increased as gestation advances and in pregnancy pathologies. The origins of increased SNAs are unclear; however, a better appreciation of the mechanism may give insight into placental ageing and factors underpinning dysfunction. We developed three models to investigate whether SNA formation results from a dynamic process of nuclear movement and to generate alternative hypotheses. SNA count and size were measured in placental explants cultured over 16 days and particles released into culture medium were quantified. Primary trophoblasts were cultured for 6 days. Explants and trophoblasts were cultured with and without cytoskeletal inhibitors. An in silico model was developed to examine the effects of modulating nuclear behaviour on clustering. In explants, neither median SNA number (108 SNA/mm(2) villous area) nor size (283 µm(2)) changed over time. Subcellular particles from conditioned culture medium showed a wide range of sizes that overlapped with those of SNAs. Nuclei in primary trophoblasts did not change position relative to other nuclei; apparent movement was associated with positional changes of the syncytial cell membrane. In both models, SNAs and nuclear clusters were stable despite pharmacological disruption of cytoskeletal activity. In silico, increased nuclear movement, adhesiveness and sites of cytotrophoblast fusion were related to nuclear clustering. The prominence of SNAs in pregnancy disorders may not result from an active process involving cytoskeleton-mediated rearrangement of syncytial nuclei. Further insights into the mechanism(s) of SNA formation will aid understanding of their increased presence in pregnancy pathologies.
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Membrana Celular/ultraestrutura , Núcleo Celular/ultraestrutura , Citoesqueleto/ultraestrutura , Placenta/ultraestrutura , Trofoblastos/ultraestrutura , Feminino , Imunofluorescência , Humanos , Gravidez , Imagem com Lapso de TempoRESUMO
With histopathology results typically taking several days, the ability to stage tumors during interventions could provide a step change in various cancer interventions. X-ray technology has advanced significantly in recent years with the introduction of phase-based imaging methods. These have been adapted for use in standard labs rather than specialized facilities such as synchrotrons, and approaches that enable fast 3D scans with conventional x-ray sources have been developed. This opens the possibility to produce 3D images with enhanced soft tissue contrast at a level of detail comparable to histopathology, in times sufficiently short to be compatible with use during surgical interventions. In this paper we discuss the application of one such approach to human esophagi obtained from esophagectomy interventions. We demonstrate that the image quality is sufficiently high to enable tumor T staging based on the x-ray datasets alone. Alongside detection of involved margins with potentially life-saving implications, staging tumors intra-operatively has the potential to change patient pathways, facilitating optimization of therapeutic interventions during the procedure itself. Besides a prospective intra-operative use, the availability of high-quality 3D images of entire esophageal tumors can support histopathological characterization, from enabling "right slice first time" approaches to understanding the histopathology in the full 3D context of the surrounding tumor environment.
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Determining the host preference of vector ticks is vital to elucidating the eco-epidemiology of the diseases they spread. Detachment of ticks from captured hosts can provide evidence of feeding on those host species, but only for those species that are feasible to capture. Recently developed, highly sensitive molecular assays show great promise in allowing host selection to be determined from minute traces of host DNA that persist in recently molted ticks. Using methods developed in Europe as a starting-point, we designed 12S rDNA mitochondrial gene probes suitable for use in a reverse line blot (RLB) assay of ticks feeding on common host species in the eastern United States. This is the first study to use the 12S mitochondrial gene in a RLB bloodmeal assay in North America. The assay combines conventional PCR with a biotin-labeled primer and reverse line blots that can be stripped and rehybridized up to 20 times, making the method less expensive and more straightforward to interpret than previous methods of tick bloodmeal identification. Probes were designed that target the species, genus, genus group, family, order, or class of eight reptile, 13 birds, and 32 mammal hosts. After optimization, the RLB assay correctly identified the current hostspecies for 99% of ticks [Amblyomma americanum (L.) and eight other ixodid tick species] collected directly from known hosts. The method identified previous-host DNA for approximately half of all questing ticks assayed. Multiple bloodmeal determinations were obtained in some instances from feeding and questing ticks; this pattern is consistent with previous RLB studies but requires further investigation. Development of this probe library, suitable for eastern U.S. ecosystems, opens new avenues for eco-epidemiological investigations of this region's tick-host systems.
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Sondas de DNA , DNA/sangue , Especificidade de Hospedeiro , Carrapatos/fisiologia , Vertebrados/genética , Animais , DNA/química , Reação em Cadeia da Polimerase , RNA Ribossômico/genética , Estados UnidosRESUMO
Lyme disease (LD), caused by the bacterium Borrelia burgdorferi and transmitted in the eastern United States by blacklegged ticks, Ixodes scapularis Say, is classified as nonendemic in Tennessee and surrounding states in the Southeast. Low incidence of LD in these states has been attributed, in part, to vector ticks being scarce or absent; however, tick survey data for many counties are incomplete or out of date. To improve our knowledge of the distribution, abundance, and Borrelia spp. prevalence of I. scapularis, we collected ticks from 1,018 hunter-harvested white-tailed deer (Odocoileus virginianus (Zimmerman)) from 71 of 95 Tennessee counties in fall 2007 and 2008. In total, 160 deer (15.7%) from 35 counties were infested with adult I. scapularis; 30 of these counties were new distributional records for this tick. The mean number of I. scapularis collected per infested deer was 5.4 +/- 0.6 SE. Of the 883 I. scapularis we removed from deer, none were positive for B. burgdorferi and one tested positive for B. miyamotoi. Deer are not reservoir hosts for B. burgdorferi; nevertheless, past surveys in northern LD-endemic states have readily detected B. burgdoreferi in ticks collected from deer. We conclude that I. scapularis is far more widespread in Tennessee than previously reported. The absence of detectable B. burgdorferi infection among these ticks suggests that the LD risk posed by I. scapularis in the surveyed areas of Tennessee is much lower than in LD-endemic areas of the Northeast and upper Midwest.
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Borrelia burgdorferi/isolamento & purificação , Cervos/parasitologia , Ixodes/microbiologia , Animais , Feminino , Doença de Lyme/transmissão , Masculino , TennesseeRESUMO
Child feeding problems are often associated with parental factors which may influence and maintain difficulties. This paper reports the development, pilot and preliminary evaluation of a group intervention for mothers of children with feeding problems. Themes for the group were derived from a survey of parents and professionals. Three pilot interventions were conducted in order to make an assessment of the feasibility, acceptability and potential for achieving change in levels of maternal mood, parenting stress and concerns related to feeding. While single case analysis revealed little change in standardised measures of mood and parenting stress, participants valued the social and emotional support offered by the group and reported improvements in concerns and maladaptive behaviours related to feeding. An intervention which provides support and a sense of a shared experience appears to have beneficial effects for mothers of children with feeding problems and therefore, may offer a constructive means of supporting this population.
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Transtornos de Alimentação na Infância/terapia , Mães/psicologia , Poder Familiar/psicologia , Apoio Social , Ansiedade , Pré-Escolar , Depressão , Emoções , Estudos de Viabilidade , Feminino , Humanos , Lactente , Recém-Nascido , Comportamento Materno , Projetos Piloto , Estresse Psicológico/psicologiaRESUMO
BACKGROUND: Endometriosis is a common cause of infertility and pelvic pain. Lectin histochemistry has shown that glycan expression is a sensitive marker of differentiation in the normal endometrium. Endometrial biopsies were taken during the implantation window from women with subfertility and advanced (stage III and IV) endometriosis to evaluate specific glycans bound by lectins from Dolichos biflorus agglutinin (DBA) and Vicia villosa agglutinin (VVA), which detect related but distinct glycan sequences regulated by progesterone action. METHODS: Endometrial tissue from 12 women with subfertility and advanced endometriosis and 11 healthy controls were taken on days 19-24 of the menstrual cycle and processed into either epoxy resin or paraffin wax. Lectin histochemistry was analysed using light microscopy to quantify the amount of glandular reaction product. RESULTS: There was a significant (P = 0.011) reduction in DBA binding to endometrium from patients with endometriosis compared with controls, which was not seen with VVA (P = 0.135). Three stage IV biopsies and one stage III biopsy completely failed to bind DBA and, of these, three showed moderate glandular binding of VVA. DBA and VVA binding differed significantly (P= 0.0039) in the endometriosis specimens whereas in controls no significant difference was detected (P = 0.812). CONCLUSION: Secretory phase glycosylation in women with advanced endometriosis differs from that in healthy women with a reduction in fucosylated N-acetylgalactosamine sequences bound by DBA. Shorter VVA-binding glycans are not significantly affected. In addition to indicating abnormalities of epithelial differentiation, these findings may be directly relevant to implantation failure, as blastocyst attachment requires a critical interaction with the epithelial glycocalyx.
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Implantação do Embrião/fisiologia , Endometriose/patologia , Endometriose/fisiopatologia , Infertilidade Feminina/fisiopatologia , Lectinas de Plantas/metabolismo , Acetilgalactosamina/metabolismo , Adulto , Feminino , Glicosilação , Humanos , Infertilidade Feminina/patologiaRESUMO
Experimentally induced endometriosis in baboons serves as an elegant model to discriminate between endometrial genes which are primarily associated with normal endometrial function and those that are changed by the presence of endometriotic lesions. Since connexin genes are characteristic of the hormonally regulated differentiation of the endometrium, we have examined connexin expression in baboon endometrium to delineate if they are altered in response to the presence of endometriotic lesions. Connexin expression in the endometrium of cycling baboons is similar to that of the human endometrium with Connexin(Cx)43 being primarily seen in the stromal compartment and Cx26 and Cx32 being present predominantly in the epithelium. Although Cx32 is up-regulated during the secretory phase, Cx26 and Cx43 are down-regulated. In the baboon model of induced endometriosis a change in connexin pattern was evident in the presence of endometriotic lesions. In the secretory phase, Cx26 and Cx32 are no longer present in the epithelium but Cx26 is now observed primarily in the stromal cells. Infusion of chorionic gonadotrophin in a manner that mimics blastocyst transit in utero failed to rescue the aberrant stromal expression of Cx26 that is associated with the presence of endometriotic lesions suggesting an impairment of the implantation process. The altered connexin pattern coupled with a loss of the channel protein in the epithelium and a gain of Cx26 in the stromal compartment suggests that the presence of lesions changes the uterine environment and thereby the differentiation programme. This aberrant expression of connexins may be an additional factor that contributes to endometriosis-associated infertility.
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Conexinas/metabolismo , Endometriose/metabolismo , Endométrio/metabolismo , Animais , Gonadotropina Coriônica/metabolismo , Conexina 26 , Conexina 43/metabolismo , Endometriose/patologia , Endométrio/patologia , Endométrio/ultraestrutura , Feminino , Imuno-Histoquímica , Ciclo Menstrual/metabolismo , Microscopia Eletrônica de Transmissão , Reação em Cadeia da PolimeraseRESUMO
Hybridisation occurs rarely in nature and experiments using interspecific transfer of embryos generally result in implantation failure. Here we show that appropriate glycosylation of the apposing surfaces of endometrium and trophoblast probably is an important factor and may play a critical role in pregnancy success. Examination of closely related species shows that each has its own specific pattern of glycosylation, or glycotype, at the fetomaternal interface and that interacting surfaces appear to show complementarity, suggesting the existence of a glycocode. Studies on a camel/llama hybrid show that for successful implantation to occur, a hybrid must have a placental glycosylation pattern similar to that of the host species, suggesting that the glycocode and appropriate glycosylation may be critical factors in the establishment and maintenance of pregnancy. This new field of reproductive glycogenetics is not only relevant to the development of new species but may also have important implications in the area of human fertility.
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Endométrio/metabolismo , Glicosilação , Hibridização Genética , Prenhez/metabolismo , Trofoblastos/metabolismo , Animais , Camelídeos Americanos , Camelus , Feminino , GravidezRESUMO
At the tips of anchoring villi, cytotrophoblast (CTB) proliferation leads to a process of multilayering in which cells lose their attachment to the villous basement membrane and develop into columns, within which they adhere to one another using desmosomes, with associated intermediate filament bundles. Non-desmosomal cadherins, tight junction proteins and other adhesion molecules are also present, suggesting that actin-associated adhesions contribute to placental anchorage. In the distal columns, cell-cell interactions diminish, cells upregulate beta1 integrins and bind to a provisional fibrinoid extracellular matrix, eventually detaching to migrate into the decidual stroma and myometrium, where interstitial and endovascular extravillous trophoblast (EVT) populations show distinct repertoires of adhesion molecules.
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Moléculas de Adesão Celular/fisiologia , Trofoblastos/fisiologia , Caderinas/fisiologia , Proliferação de Células , Efrinas/fisiologia , Feminino , Humanos , Integrinas/fisiologia , Junções Intercelulares/fisiologia , Kisspeptinas , Gravidez , Selectinas/fisiologia , Trofoblastos/citologia , Trofoblastos/ultraestrutura , Proteínas Supressoras de Tumor/fisiologiaRESUMO
In the placental villus, cells attach to basement membrane via integrin alpha6beta4 and adhere both laterally and apically to their neighbours. The most prominent adhesive specialisation seen using the electron microscope is the desmosome, which connects cytotrophoblast cells (CTB) laterally and also contributes to the attachment of CTB to the overlying syncytium. However, numerous cadherins and other junctional proteins are also present in the corresponding plasma membrane domains, indicating a multiplicity of adhesive interactions. Integrins, tight junction components and cadherins are all found in the syncytial microvillous membrane, perhaps reflecting its ability to form intersyncytial bridges. There is a wide gulf to be filled between molecular anatomy and functional studies, with much to be learned about the role of adhesion molecules in regulating villous epithelial integrity, homeostasis and growth.
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Moléculas de Adesão Celular/fisiologia , Vilosidades Coriônicas/fisiologia , Trofoblastos/fisiologia , Caderinas/fisiologia , Cateninas/fisiologia , Adesão Celular/fisiologia , Diferenciação Celular , Vilosidades Coriônicas/ultraestrutura , Desmossomos/fisiologia , Efrinas/fisiologia , Matriz Extracelular/fisiologia , Feminino , Junções Comunicantes/fisiologia , Humanos , Integrinas/fisiologia , Nectinas , Polissacarídeos/fisiologia , Gravidez , Junções Íntimas/fisiologia , Trofoblastos/citologia , Trofoblastos/ultraestruturaAssuntos
Assistência Odontológica para Doentes Crônicos , Esquizofrenia , Agendamento de Consultas , Transtorno do Deficit de Atenção com Hiperatividade/complicações , Comorbidade , Diabetes Mellitus Tipo 2/complicações , Epilepsia/complicações , Humanos , Esquizofrenia/complicações , Esquizofrenia/tratamento farmacológico , Automutilação/etiologia , Transtornos da Articulação Temporomandibular/etiologia , Traumatismos Dentários/etiologiaRESUMO
The Drosophila latheo (lat) gene was identified in a behavioral screen for olfactory memory mutants. The original hypomorphic latP1 mutant (Boynton and Tully, 1992) shows a structural defect in adult brain. Homozygous lethal lat mutants lack imaginal discs, show little cell proliferation in the CNS of third instar larvae, and die as early pupae. latP1 was cloned, and all of the above mentioned defects of hypomorphic or homozygous lethal lat mutants were rescued with a lat+ transgene. lat encodes a novel protein with homology to a subunit of the origin recognition complex (ORC). Human and Drosophila LAT both associate with ORC2 and are related to yeast ORC3, suggesting that LAT functions in DNA replication during cell proliferation.
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Proteínas de Ligação a DNA/genética , Proteínas de Drosophila , Drosophila/genética , Memória/fisiologia , Mutação/genética , Neurônios/patologia , Condutos Olfatórios/fisiopatologia , Sequência de Aminoácidos/genética , Animais , Animais Geneticamente Modificados , Encéfalo/anormalidades , Encéfalo/patologia , Encéfalo/fisiopatologia , Divisão Celular/fisiologia , Sistema Nervoso Central/patologia , Anormalidades Congênitas/genética , Drosophila/crescimento & desenvolvimento , Transtornos da Memória/genética , Dados de Sequência Molecular , Mutação/fisiologia , Complexo de Reconhecimento de Origem , Pupa/fisiologia , Homologia de Sequência de Aminoácidos , Transcrição Gênica/genética , Transgenes/fisiologiaRESUMO
Pre-eclampsia (PE) and intrauterine growth restriction (IUGR) are associated with aberrant cell turnover, including increased apoptosis, in placental villous trophoblast. The increased apoptosis is associated with exaggerated expression of p53, which promotes cell cycle arrest or apoptosis via downstream proteins such as p21 or Bax. These changes in apoptosis and p53 expression are purported to result from exposure to altered oxygen tension. Using a model of villous trophoblast turnover, we examined the effect of 20%, 6% and 1% ambient oxygen (O(2)) on apoptosis, necrosis, proliferation and expression of p53 and related regulators of cell turnover, compared to both fresh tissue. Altered O(2) tension exerted an effect on cell turnover in cultured term villous tissue: cytotrophoblast proliferation was increased by culture in 20% O(2) and reduced in 1% O(2) (median proliferative index: fresh tissue=0.32%, 20% O(2)=0.9%, 6% O(2)=0.28%, 1% O(2)=0.07%). Apoptosis was increased in all culture environments, but was significantly enhanced by culture in 1% O(2) (median apoptotic index: fresh tissue=0.64%, 20% O(2)=2.96%, 6% O(2)=3.81%, 1% O(2)=9.2%). Necrotic cell death was also increased by culture in 1% O(2) compared to 6% and 20% O(2). The expression of p53, p21 and Mdm2 in both cytotrophoblast and stromal cells was increased following culture in 1% O(2). There was no alteration in the expression of Bax or Bcl-2. This study provides evidence that p53 is elevated in trophoblast following exposure to hypoxia. The potential role of the p53-pathway in the control of cell turnover in villous trophoblast and the regulation of p53 by altered O(2) tension merits further investigation.
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Proteínas Reguladoras de Apoptose/genética , Proliferação de Células/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Oxigênio/farmacologia , Trofoblastos/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21/genética , Relação Dose-Resposta a Droga , Feminino , Genes p53 , Humanos , Necrose , Técnicas de Cultura de Órgãos , Gravidez , Proteínas Proto-Oncogênicas c-mdm2/genética , Trofoblastos/citologia , Trofoblastos/metabolismo , Trofoblastos/patologiaRESUMO
A recent study of human placental villi [Mori et al., The cytotrophoblast layer of human chorionic villi becomes thinner but maintains its structural integrity during gestation, Biol Reprod 76 (2007) 164-172] concluded that cytotrophoblast (CT) cells occupy 80% of the basal lamina (BL) surface at term and that syncytiotrophoblast (ST) does not make direct contact with the BL. Based on SPINT-1 localisation using immunofluorescence on cryosections, these conclusions run counter to previous light and electron microscopic data suggesting that term CT cells cover no more than about 24% of the BL surface. To resolve these discrepancies, we have undertaken a stereological study of term placenta using transmission electron microscopy (TEM) and a novel immunofluorescence approach. Test line lattices were randomly superimposed on TEM images of villous trophoblast from 13 normal term placentae. Intersections with the test lines were counted to assess the fractional surface of BL occupied by CT cells. After trypsin-mediated removal of syncytium, cells in whole-mounted term and first trimester villi were stained with cytokeratin 7 to identify CT and then visualised by confocal microscopy. CT formed an almost continuous layer in the first trimester. In contrast, term CT cells and their processes were found to cover only 44% (SD 14%) of the BL surface with intervening regions occupied by ST. TEM and confocal images were consistent with the concept of a network of 'octopoid' CT cells with fine processes extending from a central cell body. Our estimates of CT coverage are lower than the recent immunofluorescence estimate but greater than earlier TEM estimates. The former may have been biased by overprojection (section thickness) effects whilst the latter may be underestimates due to failure to include the fine CT cell processes. We conclude that CT cells transform from a cuboidal phenotype early in gestation to flattened cells with multiple interconnecting processes. The CT layer thins but maintains a functional network within which cells intercommunicate without compromising substance transfer via the syncytium.
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Membrana Basal/anatomia & histologia , Nascimento a Termo , Trofoblastos/ultraestrutura , Membrana Basal/fisiologia , Membrana Basal/ultraestrutura , Feminino , Humanos , Fenótipo , Placenta/anatomia & histologia , Placenta/ultraestrutura , Gravidez , Primeiro Trimestre da GravidezRESUMO
In Africa, approximately 25 million pregnant women are at risk of Plasmodium falciparum infection each year, one in four has evidence of placental involvement and up to half of these may be associated with low birth weight outcomes. In infected pregnant women, the placenta is an ideal site for the accumulation of the parasites, and this reduces in extent in subsequent pregnancies. Recent data indicate that terminal alpha2,3 sialic acid-dependent routes are central to the efficient invasion of erythrocytes with P. falciparum, however, the role in placental malaria of sialylated, or other glycoconjugates, on syncytiotrophoblast has not previously been assessed. Placental biopsies from Zambian women showed the Neu5Ac(alpha2,6)Gal/GalNAc sequences bound by the lectin from Sambucus nigra (SNA-1) to have greatly increased expression on microvillous membranes in samples with chronic P. falciparum infection showing, by electronic image analysis, a significant trend (p=0.002) compared to samples with past or no infection. This suggests a specific placental membrane response to falciparum malaria. Expression of alpha2,6-linked sialic acid, demonstrated by the binding of SNA-1, has been associated with intercellular repulsion in tissues from patients with cancer, and such repulsion resulting from increased alpha2,6 sialylation of chorionic villi could influence intervillous placental parasite density. Sialic acid expression should be examined in placental malaria to identify if this is a malaria-specific phenomenon, and to determine its relation to placental inflammation and pregnancy outcomes.
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Malária Falciparum/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Placenta/metabolismo , Complicações Parasitárias na Gravidez/metabolismo , Animais , Feminino , Humanos , Recém-Nascido , Estudos Longitudinais , Ácido N-Acetilneuramínico/química , Lectinas de Plantas/metabolismo , Plasmodium falciparum , Gravidez , Proteínas Inativadoras de Ribossomos/metabolismo , Regulação para CimaRESUMO
A number of cis- and trans-acting transcriptional factors in the flagellar regulons of Caulobacter crescentus and Salmonella typhimurium have been identified and characterized to varying degrees over the past year, bringing us closer to understanding the regulations of these complex gene hierarchies.