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1.
PLoS One ; 13(5): e0195375, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29768418

RESUMO

BACKGROUND: Prenatal exposures have known adverse effects on maternal and neonatal outcomes. Professional societies recommend routine screening for environmental, occupational, and dietary exposures to reduce exposures and their associated sequelae. OBJECTIVE: Our objective was to determine the frequency of environmental exposure screening by obstetricians and gynecologists (OBGYNs) at initial patient visits. STUDY DESIGN: Practicing OBGYNs were approached at the University of Colorado and by social media. The survey instrument queried demographics, environmental literacy, and screening practices. Statistical analysis was performed using Chi-square and two-sample t-test. RESULTS: We received 312 online survey responses (response rate of 12%). Responding OBGYNs were predominantly female (96%), board-certified (78%), generalists (65%) with a mean age of 37.1 years. Fewer than half of physicians screened for the following factors: occupational exposures, environmental chemicals, air pollution, pesticide use, personal care products, household cleaners, water source, use of plastics for food storage, and lead and mercury exposure. Eighty five percent of respondents reported that they did not feel comfortable obtaining an environmental history and 58% respondents reported that they performed no regular screening of environmental exposures. A higher frequency of screening was associated with > 4 years of practice (p = 0.001), and having read the environmental committee opinion (p = <0.001). CONCLUSION: The majority of OBGYNs did not incorporate screening for known environmental exposures into routine practice. Reading the environmental committee opinions was strongly and significantly associated with a higher rate of screening. Improving physician comfort in counseling patients may enhance screening for exposures that affect reproductive health.


Assuntos
Exposição Ambiental/análise , Ginecologia/normas , Conhecimentos, Atitudes e Prática em Saúde , Programas de Rastreamento/normas , Obstetrícia/normas , Padrões de Prática Médica/normas , Diagnóstico Pré-Natal/normas , Adulto , Atitude do Pessoal de Saúde , Estudos Transversais , Saúde Ambiental , Feminino , Humanos , Masculino , Gravidez
2.
Hum Reprod ; 30(3): 692-700, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25609240

RESUMO

STUDY QUESTION: Does polycystic ovary syndrome (PCOS) in women without pregnancy complications affect placental signal transducer and activator of transcription 3 (STAT3) and mechanistic target of rapamycin (mTOR) signaling? SUMMARY ANSWER: Placental STAT3 signaling is activated but mTOR signaling is unaffected in PCOS. WHAT IS KNOWN ALREADY: Women with PCOS have increased risk of poor pregnancy outcomes (e.g. restricted or accelerated fetal growth), indicating placental dysfunction. Placental STAT3 and mTOR pathways regulate placental function and indirectly affect fetal growth. STUDY DESIGN, SIZE, DURATION: In a case-control study, placental tissue and maternal blood were collected at delivery from 40 control pregnant women and 38 PCOS women with uncomplicated pregnancy. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with PCOS were recruited at two medical centers and pregnant controls were recruited at one of these centers. Placental mRNA expression of genes encoding proteins related to steroid action, metabolic pathways and cytokines was analyzed by quantitative RT-PCR. Phosphorylated placental STAT3 (P-STAT3) and mTOR targets was measured by western blot. Levels of sex steroids in serum were determined by mass spectrometry. MAIN RESULTS AND THE ROLE OF CHANCE: Placental P-STAT3 (Tyr-705) was increased in women with PCOS (P < 0.05) versus controls. Placental mTOR signaling was not affected in PCOS women when compared with controls. Circulating levels of androstenedione, androst-5-ene-3ß, 17ß-diol, testosterone, 5α-dihydrotestosterone and etiocholanolone glucuronide were higher and estradiol lower in women with PCOS than in controls (all P < 0.05). No correlation between sex steroid levels in serum and P-STAT3 was observed. LIMITATIONS, REASONS FOR CAUTION: Women with PCOS and pregnancy complications were excluded to avoid the confounding effects of placental pathologies, which could modify STAT3 and mTOR signaling. Moreover, 97.4% of women with PCOS in the study displayed oligoamenorrhea at diagnosis. Thus, the current findings could be restricted to PCOS women with the oligo-anovulatory phenotype without pregnancy complications. WIDER IMPLICATIONS OF THE FINDINGS: Phosphorylation of STAT3 is increased in the placenta from women with PCOS and uncomplicated pregnancies, indicating that specific metabolic placental pathways are activated in the absence of obstetric and perinatal complications. STUDY FUNDING/COMPETING INTERESTS: The work was supported by the Swedish Medical Research Council (Project No. 2011-2732 and 2014-2775); Jane and Dan Olsson Foundation, Wilhelm and Martina Lundgrens's Science Fund; Hjalmar Svensson Foundation (E.S.-V and M.M.); Adlerbert Research Foundation; Swedish federal government under the LUA/ALF agreement ALFFGBG-136481 and 429501 and the Regional Research and Development agreement (VGFOUREG-5171, -11296 and -7861). MM thanks the Becas Chile Programme (Chile) and University of Chile for financial support through a postdoctoral fellowship. There are no competing interests.


Assuntos
Síndrome do Ovário Policístico/metabolismo , Fator de Transcrição STAT3/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Expressão Gênica , Humanos , Fosforilação , Gravidez , Resultado da Gravidez , RNA Mensageiro/metabolismo , Transdução de Sinais , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Serina-Treonina Quinases TOR/metabolismo
3.
Placenta ; 35(12): 1007-12, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25454472

RESUMO

INTRODUCTION: Labor induces a myriad of changes in placental gene expression. These changes may represent a physiological adaptation inhibiting placental cellular processes associated with a high demand for oxygen and energy (e.g., protein synthesis and active transport) thereby promoting oxygen and glucose transfer to the fetus. We hypothesized that mechanistic target of rapamycin complex 1 (mTORC1) signaling, a positive regulator of trophoblast protein synthesis and amino acid transport, is inhibited by labor. METHODS: Placental tissue was collected from healthy, term pregnancies (n = 15 no-labor; n = 12 labor). Activation of Caspase-1, IRS1/Akt, STAT, mTOR, and inflammatory signaling pathways was determined by Western blot. NFĸB p65 and PPARγ DNA binding activity was measured in isolated nuclei. RESULTS: Labor increased Caspase-1 activation and mTOR complex 2 signaling, as measured by phosphorylation of Akt (S473). However, mTORC1 signaling was inhibited in response to labor as evidenced by decreased phosphorylation of mTOR (S2448) and 4EBP1 (T37/46 and T70). Labor also decreased NFĸB and PPARγ DNA binding activity, while having no effect on IRS1 or STAT signaling pathway. DISCUSSION AND CONCLUSION: Several placental signaling pathways are affected by labor, which has implications for experimental design in studies of placental signaling. Inhibition of placental mTORC1 signaling in response to labor may serve to down-regulate protein synthesis and amino acid transport, processes that account for a large share of placental oxygen and glucose consumption. We speculate that this response preserves glucose and oxygen for transfer to the fetus during the stressful events of labor.


Assuntos
Trabalho de Parto/metabolismo , Complexos Multiproteicos/metabolismo , Placenta/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Adulto , Caspase 1/metabolismo , Feminino , Humanos , Proteínas Substratos do Receptor de Insulina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Fosforilação , Gravidez , Proteínas Proto-Oncogênicas c-akt/metabolismo , Trofoblastos/metabolismo , Adulto Jovem
4.
Placenta ; 33(10): 754-62, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22831880

RESUMO

Studies in primary human trophoblasts provide critical insights into placental function in normal and complicated pregnancies. Mechanistic studies in these cells require experimental tools to modulate gene expression. Lipid-based methods to transfect primary trophoblasts are fairly simple to use and allow for the efficient delivery of nucleic acids, but potential toxic effects limit these methods. Viral vectors are versatile transfection tools of native trophoblastic or foreign cDNAs, providing high transfection efficiency, low toxicity and stable DNA integration into the trophoblast genome. RNA interference (RNAi), using small interfering RNA (siRNA) or microRNA, constitutes a powerful approach to silence trophoblast genes. However, off-target effects, such as regulation of unintended complementary transcripts, inflammatory responses and saturation of the endogenous RNAi machinery, are significant concerns. Strategies to minimize off-target effects include using multiple individual siRNAs, elimination of pro-inflammatory sequences in the siRNA construct and chemical modification of a nucleotide in the guide strand or of the ribose moiety. Tools for efficient gene targeting in primary human trophoblasts are currently available, albeit not yet extensively validated. These methods are critical for exploring the function of human trophoblast genes and may provide a foundation for the future application of gene therapy that targets placental trophoblasts.


Assuntos
Marcação de Genes/métodos , Interferência de RNA/fisiologia , Transfecção/métodos , Dependovirus/fisiologia , Feminino , Humanos , Lentivirus/fisiologia , MicroRNAs/genética , Cultura Primária de Células , RNA Interferente Pequeno/genética , Trofoblastos/metabolismo
5.
Placenta ; 32(2): 121-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21144584

RESUMO

Maternal obesity and gestational diabetes (GDM) are conditions associated with fetal overgrowth and excessive fat accumulation in the fetus, implicating an increased placental nutrient transfer in these pregnancies. Obese and GDM mothers have altered metabolism and hormone levels, including elevation of maternal circulatory lipids and pro-inflammatory cytokines. We tested the hypothesis that interleukin (IL)-6 and tumor necrosis factor (TNF)-α stimulate placental fatty acid transport, as these pro-inflammatory cytokines have been shown to affect lipid metabolism in other tissues. In cultured primary human trophoblast cells IL-6, but not TNF-α, stimulated fatty acid accumulation, as measured by BODIPY fluorescence. The increased fatty acid accumulation could not be explained by an increased expression of key components in placental fatty acid transport, such as adipophilin, fatty acid transport protein (FATP)1, FATP4, or lipoprotein lipase. In a cohort of lean and overweight/obese pregnant women, increasing maternal third trimester IL-6 plasma concentrations correlated with decreasing placental lipoprotein lipase activity. However, as no effect on lipoprotein lipase activity was observed in cultured trophoblast cells after exposure to either IL-6 or TNF-α, the correlation between maternal circulatory IL-6 levels and placental lipoprotein lipase activity at term is unlikely to represent a cause-and-effect relationship. In conclusion, high levels of IL-6 stimulate trophoblast fatty acid accumulation, which could contribute to an excessive nutrient transfer in conditions associated with elevated maternal IL-6 such as obesity and gestational diabetes.


Assuntos
Ácidos Graxos/metabolismo , Interleucina-6/farmacologia , Trofoblastos/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Células Cultivadas , Feminino , Humanos , Lipase Lipoproteica/metabolismo , Obesidade/metabolismo , Sobrepeso/metabolismo , Placenta/citologia , Placenta/metabolismo , Gravidez , Complicações na Gravidez/metabolismo , Terceiro Trimestre da Gravidez , Trofoblastos/efeitos dos fármacos
6.
Am J Physiol Cell Physiol ; 297(5): C1228-35, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19741197

RESUMO

Changes in placental nutrient transport are closely associated with abnormal fetal growth. However, the molecular mechanisms underlying the regulation of placental amino acid transporters are unknown. We demonstrate that physiological concentrations of the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha stimulate the activity of amino acid transporter system A, but not system L, in cultured human primary trophoblast cells. Both cytokines increased the gene and protein expression of the Na(+)-coupled neutral amino acid transporter (SNAT)2 isoform and upregulated SNAT1 protein expression. IL-6 increased Tyr705 phosphorylation of signal transducer and activator of transcription 3 (STAT3). In cells transfected with small interfering RNA (siRNA) targeting STAT3, the RNA and protein expression of SNAT2, but not SNAT1, was reduced and the stimulating effect of IL-6 on system A activity was abolished. Despite eliciting similar responses in amino acid transport activity and transporter expression, TNF-alpha effects on system A activity were not mediated through the JAK/STAT pathway. In conclusion, we have identified a novel regulatory pathway involving increased gene expression of the SNAT2 isoform mediated by a STAT-dependent pathway, which links IL-6 to increased activity of system A, a ubiquitously expressed transporter of neutral amino acids. From these new findings, we propose that upregulation of amino acid transporters by cytokines may contribute to increased placental nutrient transport and fetal overgrowth, which are commonly found in pregnancies complicated by maternal diabetes and obesity.


Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Regulação da Expressão Gênica , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/fisiologia , Trofoblastos/metabolismo , Sistema A de Transporte de Aminoácidos/genética , Sistema A de Transporte de Aminoácidos/fisiologia , Western Blotting , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Feminino , Expressão Gênica , Humanos , Interleucina-6 , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima
7.
Placenta ; 30 Suppl A: S4-14, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19084270

RESUMO

Workshops are an important part of the IFPA annual meeting. At the IFPA meeting 2008 diverse topics were discussed in 12 themed workshops. Topics covered included: immunology of placentation; galectins and trophoblast invasion; signaling in implantation and invasion; markers to identify trophoblast subpopulations; placental pathology; placental toxicology; stereology; placental transport of fatty acids; placental mesenchymal stem cells; comparative placentation; trophoblast and neoplasia; trophoblast differentiation. This report is a summary of the various topics covered.


Assuntos
Placenta/fisiologia , Placentação/imunologia , Trofoblastos/fisiologia , Animais , Feminino , Humanos , Placenta/imunologia , Doenças Placentárias/imunologia , Gravidez
8.
J Lipid Res ; 47(11): 2551-61, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16926441

RESUMO

The fetal demand for FFA increases as gestation proceeds, and LPL represents one potential mechanism for increasing placental lipid transport. We examined LPL activity and protein expression in first trimester and term human placenta. The LPL activity was 3-fold higher in term (n = 7; P < 0.05) compared with first trimester (n = 6) placentas. The LPL expression appeared lower in microvillous membrane from first trimester (n = 2) compared with term (n = 2) placentas. We incubated isolated placental villous fragments with a variety of effectors [GW 1929, estradiol, insulin, cortisol, epinephrine, insulin-like growth factor-1 (IGF-1), and tumor necrosis factor-alpha] for 1, 3, and 24 h to investigate potential regulatory mechanisms. Decreased LPL activity was observed after 24 h of incubation with estradiol (1 micro g/ml), insulin, cortisol, and IGF-1 (n = 12; P < 0.05). We observed an increase in LPL activity after 3 h of incubation with estradiol (20 ng/ml) or hyperglycemic medium plus insulin (n = 7; P < 0.05). To conclude, we suggest that the gestational increase in placental LPL activity represents an important mechanism to enhance placental FFA transport in late pregnancy. Hormonal regulation of placental LPL activity by insulin, cortisol, IGF-1, and estradiol may be involved in gestational changes and in alterations in LPL activity in pregnancies complicated by altered fetal growth.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Lipase Lipoproteica/biossíntese , Lipase Lipoproteica/genética , Placenta/enzimologia , Trifosfato de Adenosina/metabolismo , Transporte Biológico , Membrana Celular/metabolismo , Estradiol/farmacologia , Feminino , Humanos , Hidrocortisona/farmacologia , Insulina/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Lipídeos/química , Microvilosidades/metabolismo , Gravidez , Primeiro Trimestre da Gravidez , Fatores de Tempo
9.
Med Eng Phys ; 27(7): 591-8, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16076559

RESUMO

Medical physics education and training requires the use of extensive imaging material and specific explanations. These requirements provide an excellent background for application of e-Learning. The EU projects Consortia EMERALD and EMIT developed five volumes of such materials, now used in 65 countries. EMERALD developed e-Learning materials in three areas of medical physics (X-ray diagnostic radiology, nuclear medicine and radiotherapy). EMIT developed e-Learning materials in two further areas: ultrasound and magnetic resonance imaging. This paper describes the development of these e-Learning materials (consisting of e-books and educational image databases). The e-books include tasks helping studying of various equipment and methods. The text of these PDF e-books is hyperlinked with respective images. The e-books are used through the readers' own Internet browser. Each Image Database (IDB) includes a browser, which displays hundreds of images of equipment, block diagrams and graphs, image quality examples, artefacts, etc. Both the e-books and IDB are engraved on five separate CD-ROMs. Demo of these materials can be taken from www.emerald2.net.


Assuntos
Engenharia Biomédica/educação , Instrução por Computador/métodos , Currículo , Bases de Dados Factuais , Diagnóstico por Imagem , Educação a Distância/métodos , Educação Profissionalizante/métodos , Internet , União Europeia , Física Médica/educação , Multimídia
10.
Placenta ; 25(8-9): 753-7, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15450396

RESUMO

Intrauterine growth restriction (IUGR) is associated with significantly increased perinatal morbidity and mortality as well as cardiovascular disease and glucose intolerance in adult life. A number of disorders from genetic to metabolic, vascular, coagulative, autoimmune, as well as infectious, can influence fetal growth by damaging the placenta, leading to IUGR as a result of many possible fetal, placental and maternal disorders. Strict definitions of IUGR and of its severity are needed in order to eventually distinguish among different phenotypes, such as gestational age at onset, degree of growth restriction and presence of hypoxia. This report explores and reviews some of the most recent developments in both clinical and basic research on intrauterine growth restriction, by seeking mechanisms that involve genetic factors, utero-placental nutrient availability and vascular growth factors. New exciting findings on the genomic imprinting defects potentially associated with IUGR, and the placental anomalies associated with the decreased nutrient transport are summarized. Moreover, recent data on angiogenic growth factors as well as new information arising from application of gene chip technologies are discussed.


Assuntos
Retardo do Crescimento Fetal , Placenta/metabolismo , Placenta/patologia , Adulto , Indutores da Angiogênese/metabolismo , Feminino , Retardo do Crescimento Fetal/etiologia , Retardo do Crescimento Fetal/metabolismo , Retardo do Crescimento Fetal/patologia , Impressão Genômica , Humanos , Cooperação Internacional , Gravidez
11.
Placenta ; 25(6): 505-11, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15135233

RESUMO

In humans, the non-gastric H(+)/K(+)ATPase (ATP1AL1) has previously been shown to be expressed in the epithelia of skin, kidney and colon. In this study we tested the hypothesis that the non-gastric H(+)/K(+)ATPase is localized to the syncytiotrophoblast, the transporting epithelium of the human placenta. Microvillous (MVM) and basal plasma membranes (BM) of the syncytiotrophoblast were isolated from term placenta and membrane proteins were separated using SDS-PAGE. The ATP1AL1 protein was identified as a 114 kD band in both MVM and BM by Western blot, however, the protein was more abundant in the MVM. Using immunocytochemistry H(+)/K(+)ATPase protein was localized in MVM but not BM. We constructed primers specific for ATP1AL1 and performed RT-PCR on RNA isolated from human placenta and human kidney. A product of the expected size could be detected in both tissues after 30 cycles of amplification. The sequence identity of this 517 nucleotide product was confirmed by sequencing and found to be identical to the human non-gastric H(+)/K(+)ATPase. The activity of this proton pump appears to be low in normal healthy placental at term, however, it is speculated that MVM non-gastric H(+)/K(+)ATPase may be important in pathological states. In conclusion, non-gastric H(+)/K(+)ATPase is present in the microvillous plasma membrane of the transporting epithelia of the human placenta.


Assuntos
ATPase Trocadora de Hidrogênio-Potássio/análise , Microvilosidades/enzimologia , ATPase Trocadora de Sódio-Potássio/análise , Trofoblastos/ultraestrutura , Western Blotting , Membrana Celular/enzimologia , Eletroforese em Gel de Poliacrilamida , Epitélio/enzimologia , Feminino , ATPase Trocadora de Hidrogênio-Potássio/genética , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Humanos , Imuno-Histoquímica , Placenta/enzimologia , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/metabolismo
12.
J Clin Endocrinol Metab ; 88(6): 2831-7, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12788896

RESUMO

In contrast to classical transporting epithelia, the Na(+)/K(+) ATPase is distributed to both the microvillous membrane (MVM) and the basal membrane (BM) of the placental syncytiotrophoblast. Na(+)/K(+) ATPase is important in maintaining the electrochemical gradient for Na(+), which represents the driving force for Na(+)-coupled transport of nutrients. We hypothesized that syncytiotrophoblast Na(+)/K(+)-ATPase activity is reduced in intrauterine growth restriction (IUGR). We isolated MVM and BM from control (n = 10) and IUGR placentas (n = 11). The protein expression of Na(+)/K(+)-ATPase alpha(1)-subunit was determined by Western blotting and found to be slightly reduced in MVM isolated from IUGR (-10%; P < 0.05) placentas. Na(+)/K(+) ATPase activity was measured as the ouabain-sensitive, K(+)-dependent cleavage of the fluorescent pseudosubstrate 3-O-methylfluorescein phosphate and was reduced by 35% in MVM obtained from IUGR placentas (P < 0.02). To assess the transcriptional levels of Na(+)/K(+)-ATPase mRNA, real time PCR was used. No significant changes in steady state mRNA levels for Na(+)/K(+)-ATPase were detected. The expression of the Na(+)/K(+)-ATPase alpha(1)-subunit and Na(+)/K(+)-ATPase activity in the BM were unaffected in cases of IUGR. These data suggest that Na(+)/K(+)-ATPase activity is reduced in the MVM of placentas from IUGR pregnancies. These changes might impair the function of Na(+)-coupled transporters and contribute to the reduced growth of these fetuses.


Assuntos
Retardo do Crescimento Fetal/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Trofoblastos/enzimologia , Estudos de Casos e Controles , Membrana Celular/enzimologia , Sistemas Computacionais , Feminino , Humanos , Immunoblotting , Microvilosidades/ultraestrutura , Reação em Cadeia da Polimerase , Gravidez , RNA Mensageiro/metabolismo , ATPase Trocadora de Sódio-Potássio/genética , Trofoblastos/ultraestrutura
13.
Placenta ; 24(5): 445-52, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12744920

RESUMO

Neonates born after pregnancies complicated by diabetes or intrauterine growth restriction (IUGR) have increased incidence of hypocalcaemia. Furthermore, IUGR is associated with reduced bone mineralization in infancy and osteoporosis in adult life. We tested the hypothesis that placental calcium transport is altered in these pregnancy complications. Transport of calcium into syncytiotrophoblast basal plasma membrane (BM) vesicles was studied by rapid filtration and protein expression of Ca(2+) ATPase by Western blot. In IUGR Ca(2+) ATPase activity was increased by 48 per cent (n=13; P< 0.05) whereas protein expression was 15 per cent lower (n=13; P< 0.05) than in controls (n=16). Basal membrane ATP dependent calcium transport was unaltered in gestational diabetes (GDM) but increased by 54 per cent in insulin dependent diabetes (IDDM) compared to controls (P< 0.05; n =14). Diabetes did not affect Ca(2+) ATPase expression in BM. We have previously shown that the mid-molecular fragment of parathyroid hormone related peptide (PTHrP midmolecule) stimulates BM Ca(2+) ATPase in vitro. PTHrP midmolecule concentrations in umbilical cord plasma were measured using radioimmunoassay. The concentrations in umbilical cord plasma were increased in IUGR, but unaltered in diabetes. In conclusion, placental calcium pump is activated in IUGR and IDDM, which may be secondary to increased foetal calcium demand. We speculate that PTHrP midmolecule may be one mechanism for activating BM Ca(2+) ATPase in IUGR.


Assuntos
ATPases Transportadoras de Cálcio/metabolismo , Cálcio/metabolismo , Diabetes Mellitus/enzimologia , Retardo do Crescimento Fetal/enzimologia , Membranas Intracelulares/enzimologia , Trofoblastos/enzimologia , Adulto , Western Blotting , Diabetes Mellitus Tipo 1/enzimologia , Diabetes Gestacional/enzimologia , Feminino , Sangue Fetal/química , Humanos , Proteína Relacionada ao Hormônio Paratireóideo/análise , Gravidez , Gravidez em Diabéticas/enzimologia
14.
J Endocrinol ; 175(2): 517-24, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12429049

RESUMO

The final step in the maternal-fetal transfer of calcium in the placenta involves transport against a concentration gradient across the syncytiotrophoblast basal plasma membrane (BM). Based on animal studies, it has been proposed that parathyroid hormone-related peptide (PTHrP) plays a major role in maintaining the maternal-fetal concentration gradient of calcium. In this study, we tested the hypothesis that a highly conserved mid-region fragment (38-94) of PTHrP directly affects the ATP-dependent calcium transport across BM isolated from full-term human placentas. PTHrP (38-94) stimulated ATP-dependent calcium transport at a concentration within the physiological range (5 pg/ml) and the effect (10-38% increase) was concentration dependent over the range 5 pg/ml to 5 ng/ml (n=8; P<0.05). In contrast, PTH, PTHrP (1-34), PTHrP (67-86) and calcitonin increased BM calcium transport only at concentrations much higher than physiological. The increased calcium uptake was inhibited by the protein kinase C (PKC) inhibitor chelerythrine (n=6; P<0.05). In addition, PTHrP (38-94) increased inositol trisphosphate (IP(3)) production and PKC phosphorylation in human placental BM (n=12; P<0.05). Our data indicate that PTHrP (38-94) stimulates Ca(2+)ATPase in the human syncytiotrophoblast BM vesicles by activating the IP(3)-DAG-PKC pathway. We suggest that PTHrP (38-94) is important in maintaining the calcium concentration gradient across the placental barrier in the human.


Assuntos
Trifosfato de Adenosina/metabolismo , Cálcio/metabolismo , Hormônio Paratireóideo/metabolismo , Hormônios Peptídicos/metabolismo , Trofoblastos/metabolismo , Transporte Biológico/fisiologia , Membrana Celular/metabolismo , AMP Cíclico/biossíntese , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Feminino , Humanos , Inositol 1,4,5-Trifosfato/biossíntese , Proteína Relacionada ao Hormônio Paratireóideo , Fosforilação , Proteína Quinase C/antagonistas & inibidores
15.
Placenta ; 23(5): 386-91, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12061854

RESUMO

Many of the transport processes across the syncytiotrophoblast (ST), such as amino acid transport, are Na(+)-coupled. The maintenance of a low intracellular Na(+) concentration by Na(+)/K(+)-ATPase is therefore crucial for placental transport of nutrients and consequently, foetal growth. In pregnancies complicated by diabetes foetal growth is often accelerated despite rigorous glycemic control of the mother, however the underlying mechanisms are not fully understood. We tested the hypothesis that Na(+)/K(+)-ATPase in ST plasma membranes is up-regulated in diabetic pregnancies associated with accelerated growth. ST microvillous (MVM) and basal (BM) plasma membranes were purified from term placentas of normal pregnancies (control, n=13) and pregnancies complicated by insulin-dependent diabetes mellitus (n=7) or gestational diabetes (n=6). All mothers with diabetes gave birth to large for gestational age babies. The Na(+)/K(+)-ATPase alpha(1)-subunit protein expression (Western blot) in MVM and BM was unaltered by diabetes. Na(+)/K(+)-ATPase activity (K(+)-stimulated, ouabain-sensitive phosphatase activity) in ST plasma membranes was not affected by diabetes. This is the first study of Na(+)/K(+)-ATPase in ST membranes of the human placenta in diabetes. Our data show that accelerated foetal growth in diabetic pregnancies is not associated with elevated ST Na(+)/K(+)-ATPase protein expression or activity.


Assuntos
Diabetes Gestacional/enzimologia , Gravidez em Diabéticas/enzimologia , ATPase Trocadora de Sódio-Potássio/biossíntese , Trofoblastos/enzimologia , Adulto , Fracionamento Celular , Membrana Celular/enzimologia , Feminino , Peso Fetal/fisiologia , Idade Gestacional , Humanos , Microvilosidades/enzimologia , Tamanho do Órgão/fisiologia , Gravidez , Regulação para Cima
16.
Am J Contact Dermat ; 12(3): 166-9, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11526523

RESUMO

In spite of extensive self-regulation of the fragrance industry, fragrance ingredients are still major causes of allergic contact dermatitis. There are indications that the problem is increasing in some countries, and that many nonregulated compounds are involved in the development of allergies. The use of essential oils in fragrance compounds might add both allergenic and carcinogenic compounds to a product and the exact composition of such ingredients is difficult to control. Herein, we propose a simple strategy to decrease the risk of adverse effects of fragrance ingredients in cosmetic products. This strategy consists of four major steps: (1) limit the concentration of fragrance compound in the products, (2) follow legislation and guidelines, (3) limit the concentration of a number of well-known sensitizing fragrance chemicals, and (4) limit the concentration of essential oils and materials with unknown composition. The strategy is discussed as an alternative to animal testing and in relation to other more resource-demanding approaches to the same problem.


Assuntos
Cosméticos/normas , Dermatite Alérgica de Contato/prevenção & controle , Indústrias/normas , Alternativas aos Testes com Animais , Cosméticos/efeitos adversos , Dermatite Alérgica de Contato/etiologia , Guias como Assunto , Humanos , Cooperação Internacional , Perfumes/efeitos adversos , Óleos de Plantas/efeitos adversos
18.
Acta Radiol ; 41(5): 435-40, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11016762

RESUMO

PURPOSE: To evaluate the risk of needle track seeding or tumor cell implantation as the cause of locally recurrent breast cancer after breast conserving surgery. MATERIAL AND METHODS: We reviewed recurrences from a consecutive series of 303 clinically nonpalpable breast cancers treated with breast conserving surgery after pre-operative localization. The median mammographic follow-up was 5.4 years. The suspicion of seeding or implantation was based on the location of the recurrent lesion in comparison with the needle path in two orthogonal mammographic projections. Pre-operative percutaneous biopsies had been done in 71% (214/303) of the cases. Postoperative radiotherapy was administered to 82% (194/238) of the invasive cancers and to 28% (18/65) of the ductal cancers in situ (DCIS). RESULTS: Locally recurrent cancer occurred in 11% (33/303) of the cases. Radiotherapy demonstrated a protective effect from relapse among invasive cancers but not for DCIS. Seeding or implantation was suspected in 3 recurrent invasive cancers which had not been subject to radiotherapy. The histopathological diagnosis of the primary cancer and the recurrent cancer were the same in these cases: adenoid cystic, mucinous and tubuloductal cancer. CONCLUSION: Seeding or implantation was suspected as the cause of local recurrence in 7% (3/44) of the invasive cancers which did not receive radiotherapy.


Assuntos
Neoplasias da Mama/patologia , Mamografia , Recidiva Local de Neoplasia/patologia , Inoculação de Neoplasia , Punções/efeitos adversos , Radiografia Intervencionista , Adenocarcinoma/patologia , Adenocarcinoma/radioterapia , Adenocarcinoma/cirurgia , Adenocarcinoma Mucinoso/patologia , Adenocarcinoma Mucinoso/radioterapia , Adenocarcinoma Mucinoso/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia/métodos , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Carcinoma in Situ/patologia , Carcinoma in Situ/radioterapia , Carcinoma in Situ/cirurgia , Carcinoma Adenoide Cístico/patologia , Carcinoma Adenoide Cístico/radioterapia , Carcinoma Adenoide Cístico/cirurgia , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/radioterapia , Carcinoma Ductal de Mama/cirurgia , Feminino , Seguimentos , Humanos , Mastectomia Segmentar , Pessoa de Meia-Idade , Agulhas/efeitos adversos , Invasividade Neoplásica , Recidiva Local de Neoplasia/prevenção & controle , Punções/instrumentação , Radioterapia Adjuvante
19.
Am J Physiol Regul Integr Comp Physiol ; 279(1): R287-94, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10896893

RESUMO

Despite its importance for placental function, syncytiotrophoblast Na(+)-K(+)-ATPase has not been studied in detail. We purified syncytiotrophoblast microvillous (MVM) and basal (BM) membranes from full-term human placenta. Western blotting with isoform-specific antibodies demonstrated the presence of the alpha(1)-subunit, but not the alpha(2)- or alpha(3)-subunits, in MVM and BM. Relative density per unit membrane protein in BM was 48 +/- 1% (mean +/- SE, n = 4, P < 0.02) of that in the MVM. The activity of Na(+)-K(+)-ATPase was lower in BM (1.4 +/- 0.14 micromol. mg(-1). min(-1), n = 8, P < 0.02) than in MVM (3.9 +/- 0.25 micromol. mg(-1). min(-1)). Immunocytochemistry confirmed the distribution of Na(+)-K(+)-ATPase to MVM and BM. These findings suggest that the syncytiotrophoblast represents a type of transporting epithelium different from the classical epithelia found in the small intestine and kidney, where Na(+)-K(+)-ATPase is confined to the basolateral membrane only. This unique polarization of the Na(+) pump does not, however, preclude a net transcellular transport of Na(+) to the fetus.


Assuntos
Membrana Celular/enzimologia , Microvilosidades/enzimologia , Placenta/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Trofoblastos/enzimologia , Animais , Ligação Competitiva , Colina/farmacologia , Duodeno/citologia , Duodeno/enzimologia , Feminino , Humanos , Soros Imunes/metabolismo , Immunoblotting , Imuno-Histoquímica , Transporte de Íons/efeitos dos fármacos , Isoenzimas/metabolismo , Camundongos , Ouabaína/farmacologia , Placenta/citologia , Gravidez , Ratos , Trofoblastos/citologia
20.
Acta Oncol ; 38(5): 567-72, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10427944

RESUMO

Twenty-six patients from a randomized study of combination chemotherapy in advanced breast cancer were included in a cross-comparison between two quality of life instruments: a categorical linear analogue scale (C-LASA) based on the instrument of Priestman and Baum and a Swedish instrument developed by Glimelius et al. Quality of life was assessed on day 1 and day 10 of each chemotherapy cycle and the instruments were compared using correlation and kappa analysis. For the physical dimension, the mean correlation coefficient on day 1 was 0.89 and the kappa coefficient was 0.62; and on day 10 the correlation coefficient was 0.83 and the kappa coefficient 0.62. For the emotional dimension the correlation and kappa coefficients were 0.89 and 0.71 and 0.89 and 0.61 on days 1 and 10, respectively. The corresponding values for the global dimension were 0.76 and 0.56 and 0.80 and 0.57 on days 1 and 10, respectively. A correlation was also demonstrated over time. The instruments gave similar measurements of quality of life for chemotherapy-treated patients with advanced breast cancer, but the feasibility of the C-LASA instrument was better.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/psicologia , Qualidade de Vida , Inquéritos e Questionários/normas , Adulto , Idoso , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes
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