12 research outputs found
Effects of antenatal betamethasone on preterm human and mouse ductus arteriosus: comparison with baboon data.
BackgroundAlthough studies involving preterm infants ≤34 weeks gestation report a decreased incidence of patent ductus arteriosus after antenatal betamethasone, studies involving younger gestation infants report conflicting results.MethodsWe used preterm baboons, mice, and humans (≤276/7 weeks gestation) to examine betamethasone's effects on ductus gene expression and constriction both in vitro and in vivo.ResultsIn mice, betamethasone increased the sensitivity of the premature ductus to the contractile effects of oxygen without altering the effects of other contractile or vasodilatory stimuli. Betamethasone's effects on oxygen sensitivity could be eliminated by inhibiting endogenous prostaglandin/nitric oxide signaling. In mice and baboons, betamethasone increased the expression of several developmentally regulated genes that mediate oxygen-induced constriction (K+ channels) and inhibit vasodilator signaling (phosphodiesterases). In human infants, betamethasone increased the rate of ductus constriction at all gestational ages. However, in infants born ≤256/7 weeks gestation, betamethasone's contractile effects were only apparent when prostaglandin signaling was inhibited, whereas at 26-27 weeks gestation, betamethasone's contractile effects were apparent even in the absence of prostaglandin inhibitors.ConclusionsWe speculate that betamethasone's contractile effects may be mediated through genes that are developmentally regulated. This could explain why betamethasone's effects vary according to the infant's developmental age at birth
Is color Doppler ultrasonography reliable in diagnosing adnexal torsion? A large cohort analysis
IntroductionColor Doppler ultrasonography (CDU) is widely used to diagnose adnexal torsion (AT). However, its validity remains questionable due to its low sensitivity. Our study aimed to evaluate the accuracy of CDU for the preoperative diagnosis of AT.Material and methodsThe electronic medical records of patients who were taken to the operating room with the diagnosis of suspected AT were reviewed. Patients having surgically/pathologically-proven AT were compared with patients who were found to have a different pathology at the time of surgery. CDU validity was assessed using a 2 x 2 table and compared with a diagnostic model that consists of the Doppler findings, patient's age, and previous surgical history.ResultsAT was diagnosed correctly in 74.6% of cases. Absent Doppler flow was seen in only 18.6% of cases. Although its specificity and positive predictive value were high, CDU had very low sensitivity and negative predictive value. The combined diagnostic model exceeded CDU alone in terms of diagnostic accuracy.ConclusionsThe use of CDU alone is not a reliable modality to exclude AT. Absent Doppler flow is a sign of ovarian necrosis. Clinical correlation between CDU findings and the patient's symptoms makes the diagnosis of AT more timely and accurate
Is color Doppler ultrasonography reliable in diagnosing adnexal torsion? A large cohort analysis
IntroductionColor Doppler ultrasonography (CDU) is widely used to diagnose adnexal torsion (AT). However, its validity remains questionable due to its low sensitivity. Our study aimed to evaluate the accuracy of CDU for the preoperative diagnosis of AT.Material and methodsThe electronic medical records of patients who were taken to the operating room with the diagnosis of suspected AT were reviewed. Patients having surgically/pathologically-proven AT were compared with patients who were found to have a different pathology at the time of surgery. CDU validity was assessed using a 2 x 2 table and compared with a diagnostic model that consists of the Doppler findings, patient's age, and previous surgical history.ResultsAT was diagnosed correctly in 74.6% of cases. Absent Doppler flow was seen in only 18.6% of cases. Although its specificity and positive predictive value were high, CDU had very low sensitivity and negative predictive value. The combined diagnostic model exceeded CDU alone in terms of diagnostic accuracy.ConclusionsThe use of CDU alone is not a reliable modality to exclude AT. Absent Doppler flow is a sign of ovarian necrosis. Clinical correlation between CDU findings and the patient's symptoms makes the diagnosis of AT more timely and accurate
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Is color Doppler ultrasonography reliable in diagnosing adnexal torsion? A large cohort analysis
Color Doppler ultrasonography (CDU) is widely used to diagnose adnexal torsion (AT). However, its validity remains questionable due to its low sensitivity. Our study aimed to evaluate the accuracy of CDU for the preoperative diagnosis of AT.
The electronic medical records of patients who were taken to the operating room with the diagnosis of suspected AT were reviewed. Patients having surgically/pathologically-proven AT were compared with patients who were found to have a different pathology at the time of surgery. CDU validity was assessed using a 2 × 2 table and compared with a diagnostic model that consists of the Doppler findings, patient's age, and previous surgical history.
AT was diagnosed correctly in 74.6% of cases. Absent Doppler flow was seen in only 18.6% of cases. Although its specificity and positive predictive value were high, CDU had very low sensitivity and negative predictive value. The combined diagnostic model exceeded CDU alone in terms of diagnostic accuracy.
The use of CDU alone is not a reliable modality to exclude AT. Absent Doppler flow is a sign of ovarian necrosis. Clinical correlation between CDU findings and the patient's symptoms makes the diagnosis of AT more timely and accurate
Ultrasound prediction of Zika virus-associated congenital injury using the profile of fetal growth.
Zika virus (ZIKV) is a mosquito-transmitted flavivirus, recently linked to microcephaly and central nervous system anomalies following infection in pregnancy. Striking findings of disproportionate growth with a smaller than expected head relative to body length have been observed more commonly among fetuses with exposure to ZIKV in utero compared to pregnancies without ZIKV infection regardless of other signs of congenital infection including microcephaly. This study's objective was to determine the diagnostic accuracy of femur-sparing profile of intrauterine growth restriction for the identification of ZIKV-associated congenital injuries on postnatal testing. A retrospective cohort study of pregnant women with possible or confirmed ZIKV infection between January 1, 2016 and December 31, 2017 were included. Subjects were excluded if no prenatal ultrasound was available. A femur-sparing profile of growth restriction determined using INTERGROWTH-21st sonographic standard for head circumference to femur length (HC: FL). Congenital injuries were determined postnatally by imaging, comprehensive eye exam and standard newborn hearing screen. A total of 111 pregnant women diagnosed with ZIKV infection underwent fetal ultrasound and 95 neonates had complete postnatal evaluation. Prenatal microcephaly was detected in 5% of fetuses (6/111). Postnatal testing detected ZIKV-associated congenital injuries in 25% of neonates (24/95). A HC: FL Z-score ≤ -1.3 had a 52% specificity (95% CI 41-63%), 82% negative predictive value (NPV, 95% CI 73-88%) for the detection of ZIKV-associated congenital injuries in the neonatal period. A more stringent threshold with a Z-score ≤ -2 was associated with a 90% specificity (95% CI 81-95%), 81% NPV (95% CI 77-85%). Excluding cases of fetal microcephaly, HC: FL (Z-score ≤ -2) demonstrated a similar specificity (89%, 95% CI 81-95%) with superior NPV (87%, 95% CI 84-90%). The sonographic recognition of a normally proportioned fetus may be useful prenatally to exclude a wider spectrum of ZIKV-associated congenital injuries detected postnatally
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Zika virus and the nonmicrocephalic fetus: why we should still worry
Zika virus is a mosquito-transmitted flavivirus and was first linked to congenital microcephaly caused by a large outbreak in northeastern Brazil. Although the Zika virus epidemic is now in decline, pregnancies in large parts of the Americas remain at risk because of ongoing transmission and the potential for new outbreaks. This review presents why Zika virus is still a complex and worrisome public health problem with an expanding spectrum of birth defects and how Zika virus and related viruses evade the immune response to injure the fetus. Recent reports indicate that the spectrum of fetal brain and other anomalies associated with Zika virus exposure is broader and more complex than microcephaly alone and includes subtle fetal brain and ocular injuries; thus, the ability to prenatally diagnose fetal injury associated with Zika virus infection remains limited. New studies indicate that Zika virus imparts disproportionate effects on fetal growth with an unusual femur-sparing profile, potentially providing a new approach to identify viral injury to the fetus. Studies to determine the limitations of prenatal and postnatal testing for detection of Zika virus–associated birth defects and long-term neurocognitive deficits are needed to better guide women with a possible infectious exposure. It is also imperative that we investigate why the Zika virus is so adept at infecting the placenta and the fetal brain to better predict other viruses with similar capabilities that may give rise to new epidemics. The efficiency with which the Zika virus evades the early immune response to enable infection of the mother, placenta, and fetus is likely critical for understanding why the infection may either be fulminant or limited. Furthermore, studies suggest that several emerging and related viruses may also cause birth defects, including West Nile virus, which is endemic in many parts of the United States. With mosquito-borne diseases increasing worldwide, there remains an urgent need to better understand the pathogenesis of the Zika virus and related viruses to protect pregnancies and child health