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1.
Br J Surg ; 106(4): 367-374, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30706453

RESUMO

BACKGROUND: The effect of sarcopenia based on the total psoas muscle area (TPMA) on CT is inconclusive in patients undergoing abdominal aortic aneurysm (AAA) intervention. The aim of this prospective cohort study was to evaluate morphometric sarcopenia as a method of risk stratification in patients undergoing elective AAA intervention. METHODS: TPMA was measured on preintervention CT images of patients undergoing elective endovascular aneurysm repair (EVAR) or open aneurysm repair. Mortality was assessed in relation to preintervention TPMA using Cox regression analysis, with calculation of hazard ratios at 30 days, 1 year and 4 years. Postintervention morbidity was evaluated in terms of postintervention care, duration of hospital stay and 30-day readmission. Changes in TPMA on surveillance EVAR imaging were also evaluated. RESULTS: In total, 382 patient images acquired between March 2008 and December 2016 were analysed. There were no significant intraobserver and interobserver differences in measurements of TPMA. Preintervention TPMA failed to predict morbidity and mortality at all time points. The mean(s.d.) interval between preintervention and surveillance imaging was 361·3(111·2) days. A significant reduction in TPMA was observed in men on surveillance imaging after EVAR (mean reduction 0·63(1·43) cm2 per m2 ; P < 0·001). However, this was not associated with mortality (adjusted hazard ratio 1·00, 95 per cent c.i. 0·99 to 1·01; P = 0·935). CONCLUSION: TPMA is not a suitable risk stratification tool for patients undergoing effective intervention for AAA.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Angiografia por Tomografia Computadorizada/métodos , Procedimentos Cirúrgicos Eletivos/métodos , Procedimentos Endovasculares/métodos , Músculos Psoas/diagnóstico por imagem , Sarcopenia/diagnóstico por imagem , Idoso , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/mortalidade , Estudos de Coortes , Procedimentos Cirúrgicos Eletivos/mortalidade , Procedimentos Endovasculares/mortalidade , Feminino , Mortalidade Hospitalar/tendências , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Análise de Regressão , Análise de Sobrevida , Resultado do Tratamento
2.
Eye (Lond) ; 33(3): 492-504, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30546136

RESUMO

OBJECTIVE: To explore self-inflicted retinal burns from laser pointers in children. METHODS: Literature review of laser pointer retinal injuries in childhood and online survey of UK Consultant Ophthalmologists. A cohort of local children with self-inflicted injury is described. The matter is topical. We review progress in recent legislation and policy change in the UK. RESULTS: Four of 77 case reports of laser burns in childhood analysed reported psychological or behavioural issues. Three of four children in our cohort had such issues. Delay in diagnosis occurred in two of our patients. Structural retinal damage persisted for over 12 months in all four children (seven eyes). Our survey of UK ophthalmologists found 159 cases of injury (85% male), 80% under 20 years of age. The majority of the laser pointers were purchased online. Many patients (36%) suffered moderate vision loss (6/18 to 6/60 Snellen), while 17% (at least 11 patients) suffered severe vision loss (<6/60 Snellen). CONCLUSION: We highlight the risk of macular damage and vision loss from handheld lasers specifically in children with behavioural, learning or mental health issues. The diagnosis may be difficult or delayed in such children. In children with uncertain macular changes, ophthalmologists should explore the history for possible instances of exposure to handheld lasers pointers. Regulatory authorities and manufacturers of handheld lasers need to be aware of the risk to children. Furthermore, there is a need to better inform parents, carers and teachers of the risk of ocular self-injury from such lasers pointers.


Assuntos
Qualidade de Produtos para o Consumidor/legislação & jurisprudência , Queimaduras Oculares/epidemiologia , Lasers/efeitos adversos , Transtornos da Visão/epidemiologia , Criança , Queimaduras Oculares/prevenção & controle , Humanos , Jogos e Brinquedos , Formulação de Políticas , Comportamento Problema , Comportamento Autodestrutivo , Reino Unido/epidemiologia , Transtornos da Visão/prevenção & controle
3.
Nurs Stand ; 24(46): 35-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20701164

RESUMO

This article describes the physiological changes that take place during anaphylaxis, explores the ABCDE (airway, breathing, circulation, disability, exposure) approach to patient assessment and discusses the pharmacological interventions required to treat anaphylaxis effectively.


Assuntos
Anafilaxia/diagnóstico , Anafilaxia/terapia , Anafilaxia/enfermagem , Anafilaxia/fisiopatologia , Humanos , Avaliação em Enfermagem
4.
Placenta ; 29(8): 680-90, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18653232

RESUMO

Preeclampsia can be lethal to both mother and baby. The prominent symptoms of this syndrome are hypertension, proteinuria and oedema, resulting from an exaggerated aseptic systemic inflammatory response, triggered by placental factors shed into the maternal circulation. Syncytiotrophoblast microparticles (STBM) are one possible factor, shed when the placenta is exposed to stressors such as hypoxia/reperfusion. These can disrupt mitochondria, triggering apoptosis and necrosis, placental pathologies which are increased in preeclampsia. We tested the effects of antioxidant vitamins C (50 microM) and E (50 microM) on trophoblast in culture, using term villous cytotrophoblast preparations. Following Percoll gradient centrifugation and MHC class I expressing cell depletion of placenta digests, syncytial fragments were removed using anti-placental alkaline phosphatase antibody. This yielded cytotrophoblasts of consistently high purity. EGF (10 ng/ml) stimulated syncytialisation and hCG and progesterone production. However, mitochondrial induced apoptosis (MIA) was evident 96h post-isolation, as mitochondrial membrane potential loss and caspase 9 and caspase 3 activation. ROCK-1 cleavage and syncytiotrophoblast particle shedding increased concurrently with apoptosis induction. Vitamins blocked MIA and syncytiotrophoblast particle shedding and significantly increased hCG (p<0.005) and progesterone (p<0.02) concentrations in culture supernatants, reflecting the increased survival rates. Although more cells survived in culture, syncytialisation rate (%) was significantly reduced (p<0.005). We conclude that vitamins C and E can significantly reduce mitochondrial damage generated following syncytialisation in vitro. However, further work is required to determine whether antioxidant vitamins interfere with normal fusion processes.


Assuntos
Ácido Ascórbico/farmacologia , Placenta/efeitos dos fármacos , Nascimento a Termo , Trofoblastos/efeitos dos fármacos , Vitamina E/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Fusão Celular , Células Cultivadas , Feminino , Hormônios/metabolismo , Humanos , Placenta/fisiologia , Placenta/ultraestrutura , Gravidez , Nascimento a Termo/fisiologia , Trofoblastos/metabolismo , Trofoblastos/fisiologia , Trofoblastos/ultraestrutura
5.
Placenta ; 28(2-3): 139-51, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16480767

RESUMO

Lipid rafts are detergent-insoluble, low-density membrane domains that are rich in cholesterol and sphingolipids; caveolae are a subdomain of the biochemically defined glycolipid raft whose expression is associated with the protein caveolin-1. This protein associates with numerous signalling molecules, regulating their activity by holding them inactive. Human villous cytotrophoblasts contain caveolin-1, but levels reduce greatly during their differentiation into syncytiotrophoblast. Since caveolin-1 is a known regulator of apoptosis and trophoblast syncytialisation involves the apoptotic cascade, we hypothesised that cytotrophoblast caveolin-1 may also play a role in regulating fusion events involved in syncytium formation. The BeWo choriocarcinoma cell line has previously proved valuable for studying trophoblast syncytialisation, hence the present work was carried out to determine whether BeWo cells could be used as a model for the exploration of caveolin-1's role in regulating the syncytialisation process. Undifferentiated BeWo cells were found to express caveolin-1 in similar amounts to villous cytotrophoblasts isolated from term placenta. Lipid raft fractions prepared from these BeWo cells at confluence contained the raft-associated proteins caveolin-1 and -2, flotillin-1 and -2, stomatin and the heterotrimeric G protein, Galphaq. Confocal immunofluorescence studies revealed that caveolin-1 is internalized to the mitochondria, but not to the Golgi or endoplasmic reticulum, in subconfluent BeWo and that the protein relocates to the plasma membrane upon confluence, an observation confirmed by caveolin-1 and cytochrome c Western blotting of lipid raft fractions and mitochondria purified from confluent and subconfluent cells. Western blotting and immunofluorescence experiments comparing undifferentiated cells and those induced to differentiate using the cAMP analogue, dibutyryl cAMP, showed that BeWo syncytialisation was accompanied by a reduction in caveolin-1 levels, similar to the situation in primary villous cytotrophoblasts. Confluent, undifferentiated BeWo cultures were then used to investigate the cellular localisation of Rock-1, a protein which promotes cytoskeletal re-organisation important for syncytialisation and apoptosis. Its association with caveolin-1 was evidenced by the demonstration that the 160kDa proenzyme form of Rock-1 co-immunoprecipitates with caveolin-1 and vice versa, as well as by the co-localisation of the two proteins at the plasma membrane, as shown in immunofluorescence studies. A proportion of the total cell Rock-1 content was found in BeWo lipid raft fractions, confirming its membrane presence in confluent cells. This close association of plasmalemmal caveolin-1 with Rock-1 protein raises the possibility that caveolin-1 may regulate Rock-1 in these trophoblasts. We conclude that cell-cell contact is required for BeWo trophoblast to exhibit plasmalemmal caveolin-1; BeWo cells at confluence offer a useful model for the study of trophoblast raft behaviour during syncytialisation and for the exploration of the potential Rock-1-regulating role of caveolin-1 in this process.


Assuntos
Caveolina 1/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Microdomínios da Membrana/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Trofoblastos/metabolismo , Diferenciação Celular , Linhagem Celular Tumoral , Imunofluorescência , Expressão Gênica , Humanos , Imunoprecipitação , Microscopia Confocal , Mitocôndrias/metabolismo , Quinases Associadas a rho
6.
Ecotoxicol Environ Saf ; 62(3): 317-30, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16216625

RESUMO

Anadramous Atlantic salmon (Salmo salar L.) returning to Exploits River, Newfoundland, Canada, to spawn encounter low concentrations of thermomechanical pulp (TMP) effluent as they migrate upstream past an integrated newsprint mill. Various physiological responses of adult Atlantic salmon from the Exploits River were studied under laboratory conditions. The effects of a 6-h exposure to 0%, 6%, 12%, or 25% (v/v) TMP effluent or an increasing concentration gradient of effluent (0-25%) on cardiac output (Q ), critical swimming performance (U(crit)), hematocrit, and blood glucose, cortisol, lactate, and osmolality were examined. Relative to other treatment groups, Q during routine and low-level activity was 7-10% higher in fish exposed to at least 12% effluent. The 25% exposure group had a distinctly lower U(crit) and scope for increase in Q than the other treatment groups. These findings suggest that effluent exposure elevates physiological maintenance and repair costs, resulting in a reallocation of energetic resources.


Assuntos
Débito Cardíaco , Resíduos Industriais/efeitos adversos , Papel , Salmo salar/fisiologia , Eliminação de Resíduos Líquidos , Animais , Glicemia , Hematócrito , Hidrocortisona/metabolismo , Resíduos Industriais/análise , Ácido Láctico/sangue , Terra Nova e Labrador , Concentração Osmolar , Rios , Natação
7.
J Clin Endocrinol Metab ; 90(9): 5361-5, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15956084

RESUMO

CONTEXT: Placental urocortin has a role in the cascade of events leading to parturition by stimulating myometrial contractility and placental uterotonins secretion. OBJECTIVE: The objective of this study was to evaluate urocortin levels in maternal and fetal [umbilical cord artery (UCA) and vein (UCV)] plasma at term and preterm labor. DESIGN: The study design was a controlled cross-sectional study performed from November 2003 to June 2004. SETTING: This study was performed at the Division of Obstetrics and Gynecology, University of Siena (Siena, Italy). PATIENTS: Plasma samples were collected at term in the absence of labor (TNL; n = 27; 39.3 +/- 0.1 gestational weeks), at term spontaneous vaginal delivery (TL; n = 24; 40.1 +/- 0.2 gestational weeks), and at preterm labor (PTL; n = 19; 32.4 +/- 0.4 gestational weeks). Changes in urocortin mRNA expression were also evaluated in placentas collected from TNL (n = 11), TL (n = 11), and PTL (n = 10). INTERVENTION: Urocortin levels were measured by specific RIA. Changes in placental mRNA expression were determined by real-time quantitative RT-PCR analysis. RESULTS: Maternal and UCA plasma urocortin levels were significantly (P < 0.0001 for all) higher in TL and PTL than in TNL. Furthermore, UCA concentrations were significantly (P < 0.0001 for all) higher than and correlated with maternal concentrations (TNL: r = 0.45; P < 0.05; TL: r = 0.959; P < 0.0001; PTL: r = 0.7719; P < 0.0001). UCV levels were significantly (P < 0.001) higher in TL and PTL than in TNL and were significantly (P < 0.0001 for all) higher than and significantly (P < 0.0001 for all) correlated with maternal values, but were significantly (P < 0.0001 for all) lower than and correlated with UCA values (TNL: r = 0.9548; P < 0.0001; TL: r = 0.927; P < 0.0001; PTL: r = 0.838; P < 0.0001). Placental urocortin mRNA expression did not differ among TNL, TL, and PTL samples. CONCLUSIONS: Fetal urocortin secretion is increased in term and preterm labor. Whether these changes are a consequence rather than a cause of human parturition remains to be addressed.


Assuntos
Hormônio Liberador da Corticotropina/sangue , Sangue Fetal , Trabalho de Parto/sangue , Trabalho de Parto Prematuro/sangue , Hormônio Liberador da Corticotropina/genética , Estudos Transversais , Feminino , Idade Gestacional , Humanos , Concentração Osmolar , Placenta/metabolismo , Gravidez , RNA Mensageiro/metabolismo , Cordão Umbilical , Veias Umbilicais , Urocortinas
8.
Placenta ; 24(7): 745-57, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12852865

RESUMO

Caveolae are flask-shaped invaginations of the plasma membrane found in many cell types, particularly endothelium. A major structural component is the membrane protein caveolin-1 which associates with numerous signalling molecules, including endothelial nitric oxide (eNOS). Caveolin-1, which co-immunoprecipitates with eNOS in preparations from endothelial cells, regulates eNOS activity, holding it inactive. Controversy now exists regarding the presence of caveolae and caveolin-1 in trophoblasts, hence this study was carried out to examine whether the high levels of eNOS expressed in human syncytiotrophoblast are associated with caveolin-1, and to find out if caveolae are present in villous cytotrophoblasts and syncytiotrophoblast. Immunohistochemistry of term placentae revealed only weak labelling for caveolin-1 in the syncytiotrophoblast although the endothelium of the terminal villus vessels stained strongly. By electron microscopy, numerous caveolae were identified in the villus capillary endothelium but were extremely rare in the syncytium. Caveolin-1 staining was extensive in purified, isolated term villous cytotrophoblasts, with the purity of these cytokeratin positive cells confirmed by cytospin analysis and flow cytometry. Caveolae were clearly demonstrated in ultrastructural sections of the purified cytotrophoblasts. The time course of expression of caveolin-1 and eNOS during differentiation of villous cytotrophoblast into syncytiotrophoblast in culture was studied. Western analysis showed that caveolin-1 expression evident in day 1 whole cell lysates decreased at day 3 when the cells had syncytialized and declined further by day 6, while the levels of actin (control) remained high. eNOS expression in the same samples followed a different pattern, with the low levels in day 1 cells increasing substantially by 3 days in culture, subsiding again by day 6. eNOS association with caveolin-1 in day 1 and day 3 trophoblast cultures was evidenced by the demonstration that eNOS co-immunoprecipitates with caveolin-1 and vice versa. We conclude that human villous cytotrophoblasts express caveolin-1, which assembles into caveolae. Differentiation into syncytium results in a decrease, but not disappearance, of expression of caveolin-1 and a marked reduction of the caveolae.


Assuntos
Caveolinas/metabolismo , Membrana Celular/metabolismo , Vilosidades Coriônicas/metabolismo , Óxido Nítrico Sintase/metabolismo , Trofoblastos/metabolismo , Adulto , Western Blotting , Capilares/metabolismo , Capilares/ultraestrutura , Caveolina 1 , Membrana Celular/ultraestrutura , Células Cultivadas , Vilosidades Coriônicas/irrigação sanguínea , Vilosidades Coriônicas/ultraestrutura , Feminino , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Microscopia Eletrônica , Óxido Nítrico Sintase Tipo III , Gravidez , Trofoblastos/citologia
9.
Placenta ; 24(1): 84-91, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12495663

RESUMO

The maternal syndrome of pre-eclampsia is caused by generalized maternal endothelial cell dysfunction, arising directly or indirectly from factors of placental origin. Syncytiotrophoblast membrane microvesicular particles are shed from the placental surface into maternal blood in increased amounts in pre-eclampsia and, in vitro, both inhibit endothelial cell proliferation and cause marked changes in the morphology of the cultured cell monolayers. Because there is evidence that proteolytic activation and degradation of the underlying matrix can cause the same morphological changes, we tested the hypothesis that proteases intrinsic to syncytiotrophoblast microvillous membranes (STBM) are the cause of the in vitro endothelial changes. Purified STBM were analysed by zymography and western blotting. Although we could confirm the presence of urokinase plasminogen activator (uPA) in STBM we could demonstrate no intrinsic activity presumably because of its association with the plasminogen activator inhibitor-2 (PAI-2) which is also a component of STBM. We detected gelatinase activity and showed that it was due to the matrix metalloproteinase-9 (MMP-9). Its presence was confirmed in this location by immunohistocytochemistry. Protease inhibitors caused a small reversal of the effects of STBM on morphology and no effect on inhibition of proliferation. We conclude that the effect of STBM on endothelial cells is unlikely to be caused by intrinsic proteases.


Assuntos
Endotélio Vascular/enzimologia , Metaloproteinase 9 da Matriz/metabolismo , Pré-Eclâmpsia/enzimologia , Trofoblastos/enzimologia , Adulto , Western Blotting , Divisão Celular , Fracionamento Celular , Membrana Celular/enzimologia , Eletroforese em Gel de Poliacrilamida , Endotélio Vascular/citologia , Feminino , Humanos , Imuno-Histoquímica , Microvilosidades/enzimologia , Gravidez , Veias Umbilicais/citologia , Veias Umbilicais/enzimologia , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
10.
Placenta ; 23(1): 32-43, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11869090

RESUMO

ED(27) trophoblast-like cells were prepared from human chorionic villus samples obtained at 9 weeks gestation and have been grown continuously in vitro without phenotypic drift for nearly a decade. These cells express many trophoblast markers, including cytokeratin, placental alkaline phosphatase (PLAP), secretion of 17beta-estradiol, and a microvillous apical surface. The ED(27) cell line is a useful model system for studies of placental cell biology and has been distributed to laboratories world-wide. However, experiments to investigate their relationship to primary villous cytotrophoblast have shown that these cells do not secrete detectable amounts of human chorionic gonadotropin in culture and, when digested with trypsin, disperse into individual cells. Furthermore, immunocytochemical studies demonstrated that, unlike villous cytotrophoblasts, ED(27) cells were immunoreactive with monoclonal antibodies recognizing some HLA Class I antigens. This was not HLA-G, however, as would be expected if these cells originated from extravillous cytotrophoblasts, but rather classical HLA-A, B which is thought not to be expressed by any trophoblast subpopulations. These inconsistencies prompted us to question the authenticity of the continuous cell line as it now exists. Genetic haplotype analysis using the polymerase chain reaction (PCR) revealed that ED(27) was genetically identically to the HeLa cell line. Inasmuch as HeLa cells have never been grown in the laboratory (DAK), the only possible origin of HeLa cell contamination of ED(27) cells was the WISH cell line, and further PCR analysis revealed that this cell line was also genetically identical to HeLa. Like ED(27) cells, HeLa cells and WISH cells synthesized small amounts of estrogen and were found to express PLAP and antigens recognized by the monoclonal antibodies ED822, directed against the syncytiotrophoblast, and J1B5 directed against villous cytotrophoblast. These results point out the need for adherence to rigorous and consistent quality control measures to assure the authenticity of cell lines used as in vitro model systems.


Assuntos
Células HeLa/citologia , Trofoblastos/citologia , Adulto , Biomarcadores/análise , Linhagem Celular Transformada/citologia , Linhagem Celular Transformada/imunologia , Vilosidades Coriônicas/imunologia , Técnicas de Cultura/normas , DNA/análise , Contaminação de Equipamentos , Feminino , Citometria de Fluxo , Haplótipos , Células HeLa/imunologia , Antígenos de Histocompatibilidade Classe I/análise , Humanos , Imuno-Histoquímica , Fenótipo , Reação em Cadeia da Polimerase , Gravidez , Primeiro Trimestre da Gravidez , Trofoblastos/imunologia
11.
Genome Res ; 11(11): 1817-25, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11691845

RESUMO

We have isolated and sequenced all 23 members of the 22-kD alpha zein (z1C) gene family of maize. This is one of the largest plant gene families that has been sequenced from a single genetic background and includes the largest contiguous genomic DNA from maize with 346,292 bp to date. Twenty-two of the z1C members are found in a roughly tandem array on chromosome 4S forming a dense gene cluster 168,489-bp long. The twenty-third copy of the gene family is also located on chromosome 4S at a site approximately 20 cM closer to the centromere and appears to be the wild-type allele of the floury-2 (fl2) mutation. On the basis of an analysis of maize cDNA databases, only seven of these genes appear to be expressed including the fl2 allele. The expressed genes in the cluster are interspersed with nonexpressed genes. Interestingly, some of the expressed genes differ in their transcriptional regulation. Gene amplification appears to be in blocks of genes explaining the rapid and compact expansion of the cluster during the evolution of maize.


Assuntos
Evolução Molecular , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas , Família Multigênica , Zea mays/genética , Zeína/biossíntese , Zeína/genética , Clonagem Molecular/métodos , Dosagem de Genes , Biblioteca Gênica , Ligação Genética , Marcadores Genéticos , Dados de Sequência Molecular , Peso Molecular , Mapeamento Físico do Cromossomo/métodos
12.
FASEB J ; 15(10): 1678-93, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11481215

RESUMO

Studies in mammalian skin have shown expression of the genes for corticotropin-releasing hormone (CRH) and the related urocortin peptide, with subsequent production of the respective peptides. Recent molecular and biochemical analyses have further revealed the presence of CRH receptors (CRH-Rs). These CRH-Rs are functional, responding to CRH and urocortin peptides (exogenous or produced locally) through activation of receptor(s)-mediated pathways to modify skin cell phenotype. Thus, when taken together with the previous findings of cutaneous expression of POMC and its receptors, these observations extend the range of regulatory elements of the hypothalamic-pituitary-adrenal axis expressed in mammalian skin. Overall, the cutaneous CRH/POMC expression is highly reactive to common stressors such as immune cytokines, ultraviolet radiation, cutaneous pathology, or even the physiological changes associated with the hair cycle phase. Therefore, similar to its central analog, the local expression and action of CRH/POMC elements appear to be highly organized and entrained, representing general mechanism of cutaneous response to stressful stimuli. In such a CRH/POMC system, the CRH-Rs may be a central element.


Assuntos
Hormônio Liberador da Corticotropina/genética , Expressão Gênica , Receptores de Hormônio Liberador da Corticotropina/genética , Pele/metabolismo , Animais , Hormônio Liberador da Corticotropina/análise , RNA Mensageiro/análise , Receptores de Hormônio Liberador da Corticotropina/análise , Roedores , Pele/química , Urocortinas
13.
Exp Physiol ; 86(2): 273-81, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11429644

RESUMO

Aside from its role as a hypothalamic stress hormone, corticotrophin releasing hormone (CRH) is also a placental hormone, at least in primates. Although the function of placentally derived CRH remains to be fully elucidated, elevated CRH levels have been associated with premature labour, suggesting that the hormone may be involved in regulating the duration of pregnancy. Indeed, pregnant human myometrium expresses functional CRH receptors (CRH R1 and CRH R2 subtypes) thought to signal predominantly via the second messenger cAMP. Thus, like other cAMP-producing hormones in the myometrium such as beta(2) agonists, CRH may play a part in maintaining uterine quiescence. However, several of the CRH receptor isoforms identified to date have a reduced ability to activate adenylate cyclase, raising the question as to whether they are linked to other signal transduction pathways. Here, we discuss critically the evidence for the peptide's role in regulating contractility, both directly at the myometrium and indirectly via the fetal membranes and decidua. The possibility of a role in myometrial growth modulation is also described. Experimental Physiology (2001) 86.2, 273-281.


Assuntos
Hormônio Liberador da Corticotropina/fisiologia , Miométrio/fisiologia , Gravidez/fisiologia , Feminino , Humanos , Receptores de Hormônio Liberador da Corticotropina/fisiologia , Transdução de Sinais/fisiologia , Contração Uterina/fisiologia
14.
Int J Syst Evol Microbiol ; 51(Pt 3): 783-791, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11411698

RESUMO

Phylogenetic analyses of 35 strains including 25 previously published sequences and 10 which have been newly sequenced, representing two species of Euglena, five species of Phacus and three species of Astasia, were carried out using the SSU rDNA. Parsimony, distance and maximum-likelihood inferred phylogenies support (1) monophyly of the euglenoids, (2) kinetoplastids as the sister group, (3) the phagotrophic Petalomonas cantuscygni Cann et Pennick anchoring the base of the euglenoid lineage, (4) evolution of phototrophy within the euglenoids from a single event, (5) multiple origins of osmotrophic euglenoids and (6) polyphyly of the genera Euglena Ehrenberg and Phacus Dujardin. Analyses also indicate that Lepocinclis Perty, Trachelomonas Ehrenberg and Astasia Dujardin are polyphyletic. In addition, the results suggest that neither the Euglenales nor the Eutreptiales form a monophyletic lineage, thus questioning currently available classifications. Concerning the phagotrophic mode of nutrition, the data suggest that the feeding apparatus arose multiple times.


Assuntos
DNA Ribossômico/genética , Euglena/classificação , Euglena/genética , Euglênidos/classificação , Euglênidos/genética , Filogenia , RNA Ribossômico 18S/genética , Animais , Sequência de Bases , Primers do DNA , Funções Verossimilhança , Dados de Sequência Molecular , Reação em Cadeia da Polimerase
15.
J Eukaryot Microbiol ; 48(1): 88-94, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11249197

RESUMO

The flagellar apparatus of Ploeotia costata Farmer and Triemer was reconstructed using serial sectioning and TEM. The flagellar apparatus is similar to other euglenoids having two flagella arising from basal bodies connected by a striated fiber, and three asymmetrically arranged roots. The flagella emerge subapically from between the two ventral pellicle strips. The dorsal flagellum is 1/2 the body length and actively pulls the cell, while the ventral flagellum is twice the body length and drags along the substrate surface. The ventral and dorsal roots are on the opposite sides of their respective basal bodies, while the intermediate root is associated with the ventral flagellum on the side closest to the dorsal basal body. The dorsal root lines the dorsal side of the reservoir and after giving rise to the dorsal band lines the right side of the reservoir/canal. The ventral and intermediate roots join at the reservoir forming the intermediate-ventral root, which lines the left and ventral sides of the reservoir/canal. There was no evidence of a microtubule-reinforced pocket in P. costata. Comparisons with Ploeotia vilrea, Lentomonas applanatum, and related flagellar apparatuses led to the conclusion that the basic euglenoid flagellar structure is symplesiomorphic but with enough variation to be taxonomically diagnostic.


Assuntos
Eucariotos/classificação , Flagelos/ultraestrutura , Animais , Meios de Cultura , Eucariotos/fisiologia , Eucariotos/ultraestrutura , Microscopia Eletrônica de Varredura
16.
Placenta ; 21(2-3): 150-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10736237

RESUMO

It has been shown previously that syncytiotrophoblast microvillous membranes (STBM), isolated from normal or pre-eclampsia placentae, specifically inhibit the proliferation of cultured human umbilical vein endothelial cells (HUVEC) and disrupt the cell monolayer without causing cell death. We have previously shown that this anti-proliferative activity resides in a self-aggregating complex in which eight proteins, namely integrins alpha(5)(CD49e) and alpha(V)(CD51), dipeptidyl peptidase IV (DPP IV, CD26), alpha-actinin, transferrin receptor (TfR, CD71), transferrin, placental alkaline phosphatase (PLAP) and monoamine oxidase A (MAO-A) were identified. In the present study, we investigated which of these components causes the anti-proliferative activity of STBM. Antibodies against integrin alpha(5)and alpha(V)and DPP IV all reduced the STBM-induced inhibition of proliferation of HUVEC, which was also reversed by added fibronectin. A preparation of PLAP inhibited endothelial proliferation, but this was not due to enzymatic activity. The preparation was shown to be impure with more than 12 bands present on Coomassie blue stained SDS-PAGE gels. These included integrins alpha(5)and alpha(V), which could account, at least in part, for the inhibitory activity. We could not exclude, however, the possibility of other unidentified factors being involved. We conclude that adhesion molecules account for a major part of the anti-proliferative activity of STBM; these appear to compete for ligands in the extracellular matrix or serum with the appropriate receptors on HUVEC.


Assuntos
Moléculas de Adesão Celular/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/imunologia , Trofoblastos/imunologia , Actinina/metabolismo , Fosfatase Alcalina/metabolismo , Antígenos CD/metabolismo , Divisão Celular , Células Cultivadas , Meios de Cultura Livres de Soro , Dipeptidil Peptidase 4/metabolismo , Endotélio Vascular/metabolismo , Feminino , Humanos , Integrina alfa5 , Integrina alfaV , Microvilosidades/imunologia , Microvilosidades/metabolismo , Monoaminoxidase/metabolismo , Testes de Neutralização , Pré-Eclâmpsia/imunologia , Pré-Eclâmpsia/metabolismo , Pré-Eclâmpsia/patologia , Gravidez , Receptores da Transferrina/metabolismo , Transferrina/metabolismo , Trofoblastos/metabolismo
17.
J Clin Endocrinol Metab ; 85(2): 755-64, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10690887

RESUMO

This study examined the different molecular forms of CRH in normal and preeclampsia maternal plasma and protease-blocked placental extracts using antibodies to different regions of the CRH precursor, pro-CRH. In the absence of protease inhibitors, chromatographed normal placental extracts contained four peaks of immunoreactivity corresponding to unprocessed approximately 19-kDa pro-CRH, its approximately 8-kDa intermediate metabolite, pro-CRH125-194, its approximately 2.8-kDa midportion fragment, pro-CRH125-151, and 4.75-kDa CRH1-41. However, if protease inhibitors were included in the extraction medium, only pro-CRH and pro-CRH125-194 were found. Pro-CRH processing was more extensive in protease-blocked preeclampsia placentas than in those from normal pregnancy, with three peaks corresponding to pro-CRH, proCRH125-194, and mature CRH1-41 peptide found. Using quantitative competitive PCR, the messenger ribonucleic acid levels of CRH precursor in preeclampsia placentas were 1.7-fold higher than those in normal placentas (37.83 +/- 3.48 vs. 21.83 +/- 2.59 attomoles/microg total ribonucleic acid, respectively; P < 0.005). Preeclampsia placentas contained significantly more CRH1-41 cross-reactivity (4.72 +/- 1.22 pmol/g) than normal term placentas (1.52 +/- 0.39 pmol/g; P < 0.048) extracted in medium containing protease inhibitors. The content of pro-CRH(125+/-151)-reactive species in these extracts followed the same pattern, with more immunoreactivity detected in preeclampsia placentas (4.23 +/- 1.39 pmol/g) than in those from normal term pregnancies (1.44 +/- 0.32 pmol/g; P < 0.01). Sequential plasma samples from 10 women with normal pregnancy and 5 women with preeclampsia were assayed for pro-CRH(125-151)- and CRH(1-41)-immunoreactive species In normal pregnancy, maternal plasma CRH(1-41) immunoreactivity rose with increasing gestational age, reaching 460 +/- 48 pmol/L at term. In women with preeclampsia, CRH(1-41) levels at each gestational age point were higher than those at the equivalent stage of normal pregnancy. In contrast, the levels of pro-CRH(125-151)-immunoreactive species remained barely detectable throughout normal and preeclamptic pregnancy. Both pro-CRH and CRH(1-41), but not pro-CRH(125-151), were shown to bind to the plasma CRH-binding protein. Our findings highlight the importance of protection of placental tissue from degrading enzymes during extraction and show that most of the CRH in the human placenta exists as unprocessed pro-CRH, with very little in the form of CRH(1-41) except in preeclampsia. Our studies using maternal plasma indicate that CRH(1-41) is the only one of the pro-CRH fragments studied to be maintained in significant amounts in the maternal circulation and also the only fragment studied for which a specific plasma binding protein exists.


Assuntos
Hormônio Liberador da Corticotropina/metabolismo , Pré-Eclâmpsia/metabolismo , Gravidez/metabolismo , Precursores de Proteínas/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Células CHO , Hormônio Liberador da Corticotropina/sangue , Hormônio Liberador da Corticotropina/química , Hormônio Liberador da Corticotropina/genética , Cricetinae , Feminino , Humanos , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/metabolismo , Placenta/metabolismo , Gravidez/sangue , Precursores de Proteínas/sangue , Precursores de Proteínas/química , Precursores de Proteínas/genética , RNA Mensageiro/metabolismo , Valores de Referência
18.
Am J Obstet Gynecol ; 182(2): 351-7, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10694336

RESUMO

OBJECTIVE: The aim of this study was to search for activation markers of peripheral leukocytes in experimental preeclampsia in the rat. STUDY DESIGN: Experimental preeclampsia was induced in 14-day-pregnant rats by infusion of endotoxin (1.0 microg/kg body weight). For comparison, rats with normal pregnancies that were infused with sodium chloride solution and cyclic rats that were infused with either endotoxin or sodium chloride solution were used. At various points before and after the infusion, blood samples were withdrawn and analyzed by means of whole-blood flow cytometry to evaluate expression of inflammation-associated adhesion molecules (CD11b, CD11a, CD49d, and CD62L) and CD14 on the leukocytes. RESULTS: Normal pregnancy was associated with increased CD11b (granulocytes and monocytes), CD11a (monocytes and lymphocytes), and CD49d (granulocytes, monocytes, and lymphocytes) expression. In addition to these changes found in normal pregnancy, reduced CD62L and increased CD11a and CD49d expression was found on granulocytes after endotoxin treatment of pregnant rats. No effect of endotoxin was observed in cyclic rats. CONCLUSION: Leukocytes of rats with experimental preeclampsia and, to a lesser extent, those of rats with normal pregnancies had an activated phenotype. These results are consistent with our previous findings in human subjects and suggest that (experimental) preeclampsia results from a generalized inflammatory response.


Assuntos
Leucócitos/imunologia , Pré-Eclâmpsia/etiologia , Animais , Antígenos CD/sangue , Antígenos CD11/sangue , Endotoxinas/efeitos adversos , Feminino , Citometria de Fluxo , Granulócitos/química , Integrina alfa4 , Selectina L/sangue , Leucócitos/fisiologia , Receptores de Lipopolissacarídeos/sangue , Linfócitos/química , Masculino , Monócitos/química , Pré-Eclâmpsia/imunologia , Gravidez , Ratos , Ratos Wistar
19.
Br J Obstet Gynaecol ; 106(5): 439-45, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10430194

RESUMO

OBJECTIVE: To determine whether corticotrophin releasing hormone plays a role in the regulation of tone in term nonlabouring human myometrium. SETTING: A teaching hospital research laboratory. SAMPLE: Thirty-seven women undergoing elective nonlabour caesarean section under regional anaesthesia. METHODS: Human corticotrophin releasing hormone (1, 10, 100 nmol/L) was added to strips of term, nonlabouring myometrium mounted in an organ bath, and the effect on spontaneous, oxytocin (1 nmol/L) or prostaglandin F2alpha (100 nmol/L) stimulated contractions determined. Cyclic adenosine monophosphate (cAMP) content of the tissue was also determined by enzyme immunoassay. RESULTS: Corticotrophin releasing hormone did not affect myometrial tension development in any of the experimental protocols. cAMP increased transiently after addition of corticotrophin releasing hormone (166.7 +/- 12.7% at 1 minute) but this was not reflected by any change in tension. CONCLUSIONS: This study suggests that despite high maternal plasma concentrations of corticotrophin releasing hormone in pregnancy at term, this peptide is unlikely to play a direct role in the control of myometrial contractility in nonlabouring myometrium.


Assuntos
Hormônio Liberador da Corticotropina/farmacologia , Miométrio/efeitos dos fármacos , Contração Uterina/efeitos dos fármacos , Cesárea , Feminino , Humanos , Ocitocina/farmacologia , Gravidez
20.
J Eukaryot Microbiol ; 46(2): 217-23, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10361741

RESUMO

The euglenoids are an ancient and extremely diverse lineage of eukaryotic flagellates with unclear relationships among taxa. Synapomorphies for the euglenoids include a surface pellicle and a closed mitosis with a series of separate sub-spindles. The taxonomy currently in use is inconsistent with the available data and needs revision. Most euglenoid phylogenies are largely intuitive reconstructions based on a limited number of morphological characters. Therefore, we have added molecular characters from the Small Subunit (SSU) rDNA to generate an overall phylogenetic framework for the euglenoids. SSU rDNA sequences from photosynthetic, osmotrophic, and phagotrophic euglenoids were aligned based on secondary structure. Phylogenetic analysis using the conserved areas of the sequence was performed using parsimony, maximum likelihood, and distance methods. Trees derived using different criteria are in agreement. The euglenoids form a distinct monophyletic clade with phagotrophic members diverging prior to the phototrophic and osmotrophic members. Among photosynthetic members, the biflagellate form diverged prior to the uniflagellate form. Additionally, the genus Euglena appears to be paraphyletic, with osmotrophic taxa, such as Astasia and Khawkinea, diverging independently within the clade containing the photosynthetic genus Euglena.


Assuntos
DNA Ribossômico/genética , Euglênidos/classificação , Euglênidos/genética , Filogenia , Animais , DNA de Protozoário/genética , Euglênidos/crescimento & desenvolvimento , Genes de RNAr
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