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1.
Ultrasound Obstet Gynecol ; 58(1): 121-126, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33411387

RESUMO

OBJECTIVES: To determine the rate of recurrent Cesarean scar pregnancy (CSP) in our clinical practices and to evaluate whether the mode of treatment of a CSP is associated with the risk of recurrent CSP, as well as to review the published literature on recurrent CSP. METHODS: We performed a retrospective search of our six obstetric and gynecological departmental ultrasound databases for all CSPs and recurrent CSPs between 2010 and 2019. We extracted various data, including number of CSPs with follow-up, number of cases attempting and number achieving pregnancy following treatment of CSP and number of recurrent CSPs, as well as details of the treatment of the original CSP. After analyzing the clinical data, we evaluated whether the mode of treatment terminating the previous CSP was associated with the risk of recurrent CSP. We also performed a PubMed search for: 'recurrent Cesarean scar pregnancy' and 'recurrent Cesarean scar ectopic pregnancy'. Articles were reviewed for year of publication, and extraction and analysis of the same data as those obtained from our departmental databases were performed. RESULTS: Our database search identified 252 cases of CSP. The overall rate of clinical follow-up ranged between 71.4% and 100%, according to treatment site (mean, 90.9%). Among these, 105 women had another pregnancy after treatment of the previous CSP. Of these, 36 (34.3%) pregnancies were recurrent CSP, with 27 women having a single recurrence and three women having multiple recurrences, one with two, one with three and one with four. We did not find any particular single or combination treatment mode terminating the previous CSP to be associated with recurrent CSP. The literature search identified 17 articles that yielded sufficient information for us to evaluate their reported prevalence of recurrent CSP. These reported 1743 primary diagnoses of CSP, of which 944 had reliable follow-up. Data were available for 489 cases that attempted to conceive again after treatment of a previous CSP, and on the 327 pregnancies achieved. Of these, 67 (20.5%) were recurrent CSP. CONCLUSIONS: On the basis of our pooled clinical data and review of the literature, recurrent CSP is apparently more common than was previously assumed based upon mostly single-case reports or series with few cases. This should be borne in mind when counseling patients undergoing treatment for CSP regarding their risk of recurrence. We found no obvious causal relationship or association between the type of treatment of the previous CSP and recurrence of CSP. Patients who become pregnant after treatment of a CSP should be encouraged to have an early (5-7-week) first-trimester transvaginal scan to determine the location of the gestation. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Cesárea/efeitos adversos , Cicatriz/complicações , Complicações Pós-Operatórias/epidemiologia , Gravidez Ectópica/epidemiologia , Adulto , Bases de Dados Factuais , Feminino , Humanos , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Gravidez , Gravidez Ectópica/diagnóstico por imagem , Gravidez Ectópica/etiologia , Recidiva , Estudos Retrospectivos , Fatores de Risco , Ultrassonografia Pré-Natal/estatística & dados numéricos
2.
Artigo em Inglês | MEDLINE | ID: mdl-31186605

RESUMO

With the improving energy resolution of transitionedge sensor (TES) based microcalorimeters, performance verification and calibration of these detectors has become increasingly challenging, especially in the energy range below 1 keV where fluorescent atomic X-ray lines have linewidths that are wider than the detector energy resolution and require impractically high statistics to determine the gain and deconvolve the instrumental profile. Better behaved calibration sources such as grating monochromators are too cumbersome for space missions and are difficult to use in the lab. As an alternative, we are exploring the use of pulses of 3 eV optical photons delivered by an optical fiber to generate combs of known energies with known arrival times. Here, we discuss initial results of this technique obtained with 2 eV and 0.7 eV resolution X-ray microcalorimeters. With the 2 eV detector, we have achieved photon number resolution for pulses with mean photon number up to 133 (corresponding to 0.4 keV).

3.
Artigo em Inglês | MEDLINE | ID: mdl-31160861

RESUMO

Time-division multiplexing (TDM) is the backup readout technology for the X-ray Integral Field Unit (X-IFU), a 3,168-pixel X-ray transition-edge sensor (TES) array that will provide imaging spectroscopy for ESA's Athena satellite mission. X-0IFU design studies are considering readout with a multiplexing factor of up to 40. We present data showing 40-row TDM readout (32 TES rows + 8 repeats of the last row) of TESs that are of the same type as those being planned for X-IFU, using measurement and analysis parameters within the ranges specified for X-IFU. Singlecolumn TDM measurements have best-fit energy resolution of (1.91 ± 0.01) eV for the Al Kα complex (1.5 keV), (2.10 ± 0.02) eV for Ti Kα (4.5 keV), (2.23 ± 0.02) eV for Mn Kα (5.9 keV), (2.40 ± 0.02) eV for Co Kα (6.9 keV), and (3.44 ± 0.04) eV for Br Kα (11.9 keV). Three-column measurements have best-fit resolution of (2.03 ± 0.01) eV for Ti Kα and (2.40 ± 0.01) eV for Co Kα. The degradation due to the multiplexed readout ranges from 0.1 eV at the lower end of the energy range to 0.5 eV at the higher end. The demonstrated performance meets X-IFU's energy-resolution and energy-range requirements. True 40-row TDM readout, without repeated rows, of kilopixel scale arrays of X-IFU-like TESs is now under development.

4.
J Low Temp Phys ; 193(5-6): 687-694, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31359888

RESUMO

The X-ray integral field unit (X-IFU) is a cryogenic spectrometer for the Advanced Telescope for High ENergy Astrophysics (ATHENA). ATHENA is a planned next-generation space-based X-ray observatory with capabilities that surpass the spectral resolution of prior missions. Proposed device designs contain up to 3840 transition edge sensors, each acting as an individual pixel on the detector, presenting a unique challenge for wiring superconducting leads in the focal plane assembly. In prototypes that require direct wiring, the edges of X-IFU focal plane have hosted aluminum wirebonding pads; however, indium (In) 'bumps' deposited on an interface layer such as molybdenum nitride (MoN) can instead be used as an array of superconducting interconnects. We investigated bumped MoN:In structures with different process cleans and layer thicknesses. Measurements of the resistive transitions showed variation of transition temperature T c as a function of bias and generally differed from the expected bulk T c of In (3.41 K). Observed resistance of the In bump structures at temperatures below the MoN transition (at 8.0 K) also depended on the varied parameters. For our proposed X-IFU geometry (10 µm of In mated to a 1-µm In bump), we measured a minimum T c of 3.14 K at a bias current of 3 mA and a normal resistance of 0.59 mΩ per interconnect. We also investigated the design and fabrication of superconducting niobium (Nb) microstrip atop flexible polyimide. We present a process for integrating In bumps with the flexible Nb leads to enable high-density wiring for the ATHENA X-IFU focal plane.

5.
J Low Temp Phys ; 193(3-4): 321-327, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31186584

RESUMO

We have specialized astronomical applications for X-ray microcalorimeters with superconducting transition edge sensors (TESs) that require exceptionally good TES performance, but which operate in the small-signal regime. We have therefore begun a program to carefully characterize the entire transition surface of TESs with and without the usual zebra stripes to see if there are reproducible local "sweet spots" where the performance is much better than average. These measurements require precise knowledge of the circuit parameters. Here, we show how the Shapiro effect can be used to precisely calibrate the value of the shunt-resistor. We are also investigating the effects of stress and external magnetic fields to better understand reproducibility problems.

6.
Artigo em Inglês | MEDLINE | ID: mdl-28804229

RESUMO

We are developing superconducting transition-edge sensor (TES) microcalorimeter focal planes for versatility in meeting specifications of X-ray imaging spectrometers including high count-rate, high energy resolution, and large field-of-view. In particular, a focal plane composed of two sub-arrays: one of fine-pitch, high count-rate devices and the other of slower, larger pixels with similar energy resolution, offers promise for the next generation of astrophysics instruments, such as the X-ray Integral Field Unit (X-IFU) instrument on the European Space Agency's Athena mission. We have based the sub-arrays of our current design on successful pixel designs that have been demonstrated separately. Pixels with an all gold X-ray absorber on 50 and 75 micron scales where the Mo/Au TES sits atop a thick metal heatsinking layer have shown high resolution and can accommodate high count-rates. The demonstrated larger pixels use a silicon nitride membrane for thermal isolation, thinner Au and an added bismuth layer in a 250 micron square absorber. To tune the parameters of each sub-array requires merging the fabrication processes of the two detector types. We present the fabrication process for dual production of different X-ray absorbers on the same substrate, thick Au on the small pixels and thinner Au with a Bi capping layer on the larger pixels to tune their heat capacities. The process requires multiple electroplating and etching steps, but the absorbers are defined in a single ion milling step. We demonstrate methods for integrating heatsinking of the two types of pixel into the same focal plane consistent with the requirements for each sub-array, including the limiting of thermal crosstalk. We also discuss fabrication process modifications for tuning the intrinsic transition temperature (Tc) of the bilayers for the different device types through variation of the bilayer thicknesses. The latest results on these "hybrid" arrays will be presented.

7.
J Low Temp Phys ; 167(3-4): 214-219, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-26069348

RESUMO

At SRON we are studying the performance of a Goddard Space Flight Center single pixel TES microcalorimeter operated in an AC bias configuration. For x-ray photons at 6 keV the pixel shows an x-ray energy resolution ΔEFWHM =3.7 eV, which is about a factor 2 worse than the energy resolution observed in an identical DC-biased pixel. In order to better understand the reasons for this discrepancy we characterised the detector as a function of temperature, bias working point and applied perpendicular magnetic field. A strong periodic dependency of the detector noise on the TES AC bias voltage is measured. We discuss the results in the framework of the recently observed weak-link behaviour of a TES microcalorimeter.

8.
Biol Reprod ; 63(1): 294-300, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10859271

RESUMO

Episialin, which is found on the apical membrane of human endometrial epithelium, has been postulated to act as an antiadhesive factor through the steric hindrance generated by its extensively glycosylated structure. The present studies were designed to test this hypothesis in an in vitro model of endometrial-blastocyst attachment. Episialin was expressed in human endometrial carcinoma cells (HEC-1A > RL95-2), and attachment of JAr choriocarcinoma cells to the endometrial cell monolayers was inversely related to episialin expression. Treatment of endometrial monolayers with type III sialidase increased JAr binding, and this increase was suppressed by HMFG1, a monoclonal antibody specific for episialin. The effects of sialidase appear to have resulted from a contaminant protease rather than from a loss of sialic acid residues, because sialidase preparations other than type III were ineffective. After sialidase treatment, conditioned medium from cells treated with type III sialidase contained more episialin than medium from cells treated with other sialidase preparations. Similar attachment-assay results were obtained using O-sialoglycoprotein endopeptidase; after treatment, the increase in JAr binding (>50%) was suppressed by the antiepisialin antibody. These results demonstrate for the first time that episialin acts as an antiadhesive agent in a model of human endometrial-blastocyst attachment.


Assuntos
Blastocisto/citologia , Implantação do Embrião/fisiologia , Endométrio/citologia , Mucina-1/fisiologia , Blastocisto/metabolismo , Carcinoma , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Coriocarcinoma , Endométrio/metabolismo , Feminino , Humanos , Metaloendopeptidases/metabolismo , Metaloendopeptidases/farmacologia , Neuraminidase/metabolismo , Neuraminidase/farmacologia , Células Tumorais Cultivadas
10.
Female Patient ; 16(11): 17-24, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12317779

RESUMO

PIP: A growing number of US women are delaying childbirth until their late 30s. Pregnant women 35 years old face various risks including genetic disorders, prenatal medical and obstetric complications, intrapartum complications, and perinatal and neonatal morbidity and mortality. With each passing year, the risk of chromosomal abnormality such as Down's syndrome increases. Physicians perform chorionic villus sampling (CVS) between 9-11 weeks gestation and amniocentesis between 16-18 weeks to detect chromosomal abnormalities. CVS carries the higher risk of spontaneous abortion (1-2%). 35-year old pregnant women are more likely to suffer from hypertension and gestational diabetes than younger women. Yet their incidence remains at an acceptable level. Older pregnant women tend to also be at risk of several antepartum obstetric complications such as gestational bleeding, abruptio placentae, and placenta previa. The likelihood of cesarean section and dysfunctional labor is greater among 35-year old pregnant women. Between 1974 and 1978, older mothers were 4 times more likely to die than young mothers, but by 1982 the overall maternal mortality rate fell by 50%. The main causes of death among older mothers were hemorrhage, embolism, and hypertensive conditions. Positive effects of advanced maternal age were less worry about and better adjustment to pregnancy, cautiousness, and more likely to consult their physicians. Advanced maternal age tends not to effect neonatal outcome other than chromosomal anomalies. Physicians should not allow the pregnancy of 35-year old mothers to go beyond 42 weeks' gestation. Despite the minimal increased risks, 35-year old women should not allow their advanced age to be an absolute barrier to reproductive decisions. Obstetricians should conduct thorough and appropriate antepartum testing and surveillance, however.^ieng


Assuntos
Amniocentese , Cesárea , Anormalidades Congênitas , Diabetes Mellitus , Morte Fetal , Técnicas Genéticas , Hipertensão , Mortalidade Infantil , Programas de Rastreamento , Mortalidade Materna , Morbidade , Complicações na Gravidez , Resultado da Gravidez , Gravidez , Cuidado Pré-Natal , Ultrassom , Fatores Etários , América , Técnicas de Laboratório Clínico , Doenças e Anormalidades Congênitas, Hereditárias e Neonatais , Atenção à Saúde , Demografia , Países Desenvolvidos , Diagnóstico , Doença , Cirurgia Geral , Saúde , Serviços de Saúde , Idade Materna , Serviços de Saúde Materna , Centros de Saúde Materno-Infantil , Mortalidade , América do Norte , Procedimentos Cirúrgicos Obstétricos , Pais , População , Características da População , Dinâmica Populacional , Atenção Primária à Saúde , Reprodução , Terapêutica , Estados Unidos , Doenças Vasculares
11.
J Perinatol ; 9(4): 369-71, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2593009

RESUMO

We examined the exactness of the timing of the 1-hour glucose sample following a 50-g oral glucose challenge as a critical variable in interpretation of the test. Heparin locks were placed in 45 pregnant patients between 25 and 28 weeks' gestation, and 5 patients between 30 and 33 weeks' gestation. Venous samples were taken at intervals of 50, 60, and 70 minutes from completion of the ingestion of a 50-g oral glucose load. We found all of the nine possible patterns of blood glucose values that can derive from three sequential values. There was no consistent relationship between these 60 +/- 10 minute values. Two of the patients had a 60-minute value greater than 140 mg/dL, but a 50- or 70-minute value that was less than 140 mg/dL. Four of the patients had a 50- or 70-minute value that was greater than 140 mg/dL, but a 60-minute value that was less than 140 mg/mL. The range of results in this study reflects a continuum of values that change rapidly over time and in patterns that are not predictable. We conclude that accurate timing is important to avoid erroneous interpretation of the 1-hour glucose screen.


Assuntos
Glicemia/análise , Gravidez em Diabéticas/diagnóstico , Adolescente , Adulto , Feminino , Teste de Tolerância a Glucose , Humanos , Gravidez , Fatores de Tempo
12.
J Reprod Med ; 34(11): 880-3, 1989 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2585388

RESUMO

Dilation-and-evacuation procedures were performed on 13 critically ill women between 20 and 24 weeks of gestation. There were no complications. The procedure can play a significant role in the management of selected critically ill women.


PIP: A review of 13 cases of second trimester termination at 20-24 weeks by dilation and evacuation after insertion of laminaria in women with critical illness is presented. The patients ranged in age from 17-41, parity from 0-5, and diagnoses covered a wide range, including hematologic, respiratory, vascular, gastrointestinal, cardiac systems, malignancies, autoimmune disorders and infections, as well as several with multiple problems, including intravenous drug use. Most were the result of late diagnosis or late presentation. Procedures were performed according to a standard protocol by 1 physician, from 1983- 1987, using iv meperidine and diazepam sedation and paracervical block, 12 after laminaria insertion. Amniotomy and evacuation with large ovum forceps were followed by oxytocin and sharp curettage. There were no complications in this series. The dilation and curettage method is preferable in such cases because the timing of the procedure can be planned for maximal use of facilities and staff, the patient is spared by unattended delivery, the length of the abortion process is minimal, and incidence of infection and retained placenta is lower. Need for lengthy analgesia and fluid monitoring is reduced, an advantage for many critically ill women. This approach is best done by a physician with specific experience, in a setting capable of managing severe complications.


Assuntos
Aborto Terapêutico/métodos , Cuidados Críticos , Dilatação e Curetagem/métodos , Complicações na Gravidez/prevenção & controle , Aborto Terapêutico/efeitos adversos , Adolescente , Adulto , Dilatação e Curetagem/efeitos adversos , Feminino , Humanos , Monitorização Fisiológica , Gravidez , Segundo Trimestre da Gravidez
13.
Am J Obstet Gynecol ; 161(4): 857-60, 1989 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2679104

RESUMO

Currently in the United States there is widespread agreement that obstetric ultrasonography should be performed when indicated, based on a beneficence-based calculus. However, there is considerable uncertainty that routine ultrasonography is similarly indicated for every pregnant woman. We argue that the standard of care demands that prenatal informed consent for sonogram be accepted as an indication for the prudent use of obstetric ultrasonography performed by qualified personnel. Prenatal informed consent for sonogram, a primarily autonomy-based indication, should be given the same weight in clinical judgment and practice as the beneficence-based indications listed by the National Institutes of Health consensus panel.


Assuntos
Consentimento Livre e Esclarecido , Autonomia Pessoal , Gestantes , Diagnóstico Pré-Natal , Medição de Risco , Ultrassonografia , Beneficência , Consenso , Revelação , Ética Médica , Feminino , Humanos , Gravidez , Incerteza , Estados Unidos
14.
Am J Obstet Gynecol ; 161(3): 753-6, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2675605

RESUMO

Macrosomia is a potential but often overlooked consequence of the postdate pregnancy. A total of 317 consecutive patients with well-dated pregnancies who were seen because of fetal surveillance at greater than 41 weeks' gestation had an estimation of the fetal weight based on femur length and abdominal circumference at the initial visit. The incidence of macrosomia at 41 weeks' gestation was 25.5%. There was a higher incidence of cesarean section because of arrest and protraction disorders in the postdate pregnancies in which the infant was macrosomic (22%) versus those in which the infant was not macrosomic (10%, p less than 0.01). In a control group of 100 consecutive women delivered between 38 and 40 weeks' gestation, the incidence of macrosomia was 4%, significantly lower than the rate in the postdate patients (p less than 0.01). Incidence of cesarean section because of arrest and protraction disorders was significantly lower in this group (6%, p less than 0.05). The sensitivity and specificity of an estimated fetal weight greater than 4000 gm to predict a birth weight greater than 4000 gm were 60.5% and 90.7%, respectively, with a positive predictive value of 70% and a negative predictive value of 87%. We conclude that routine ultrasonographic screening for macrosomia may be a valuable adjunct to current fetal surveillance protocols used in the postdate pregnancy.


Assuntos
Macrossomia Fetal/diagnóstico , Monitorização Fetal , Programas de Rastreamento , Gravidez Prolongada , Diagnóstico Pré-Natal , Ultrassonografia , Cesárea , Feminino , Macrossomia Fetal/epidemiologia , Idade Gestacional , Humanos , Recém-Nascido , Criança Pós-Termo , Valor Preditivo dos Testes , Gravidez
16.
Radiology ; 116(02): 413-4, 1975 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1153746

RESUMO

A white male teenager with carcinoma of the breast had received radiation therapy for an asymptomatic enlarged thymus on the second, fourth and seventh days of life. The dose delivered to the infant breasts, the latent period, and the unusually young age of the patient suggest that the malignancy was related to the course of radiotherapy.


Assuntos
Adenocarcinoma/etiologia , Neoplasias da Mama/etiologia , Doenças do Recém-Nascido/radioterapia , Radioterapia/efeitos adversos , Hiperplasia do Timo/radioterapia , Adolescente , Humanos , Recém-Nascido , Masculino , Dosagem Radioterapêutica
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