ISSN:0040-3709    

DOI:10.1002/tera.1420480502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractHuman neural tube closure is believed to be a continuous process that begins in the cervical region and progresses both rostrally and caudally. In contrast, an intermittent pattern of anterior neural tube closure has been demonstrated in rodents. Based on individual case photographs, a similar pattern of anterior neural tube closure, with multiple sites of closure, may also exist in humans. We report a human fetus with two distinct anterior neural tube defects separated by a cutaneous and mesenchymal bridge. The two defects occurred within distinct closure sites predicted by the murine model, one falling within closure II and the second within closure IV. Although one defect had adherent amniotic bands, evidence is presented to support a primary dysraphy rather than disruption from an amniotic band. This case provides further evidence supporting an intermittent pattern of anterior neural tube closure in human embryogenesis. © 1993 Wiley‐Liss,

ISSN:0040-3709    

DOI:10.1002/tera.1420480503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractPregnant Swiss albino mice were exposed to 3.5 MHz diagnostic ultrasound for 10 min (upper limit for ISPTP= 1 W/cm2and for ISATA= 240 m W/cm2, acoustic power = ∼65 m W) on day 3.5 (preimplantation period), 6.5 (early organogenesis period), 11.5 (late organogenesis period), or 14.5 (early fetal period) of gestation. The offspring were observed for changes in litter size at birth, and sex ratio at 4 weeks of age, and postnatal mortality and growth retardation up to 6 weeks of age. No significant difference from control in litter size or sex ratio was observed in the offspring exposed to ultrasound on any of the gestation days studied. Exposure at the early organogenesis period produced a marginally significant increase in the postnatal mortality. A significant number of ultrasound exposed animals showed lesser body weights than the control group. However this growth retardation was transient and the normal growth pattern was restored by 6 weeks of age. It is concluded that the early stages in mouse gestation may be sensitive to the lethal effects of ultrasound than the later stages of pregnancy. Even though a small increase in the postnatal mortality was observed in the ultrasound exposed animals, the normal growth was not affected in the surviving animals except for a transient growth retardation. Low birth weight may be a characteristic effect of exposure only at the preimplantation period. © 1993 Wiley‐Liss

ISSN:0040-3709    

DOI:10.1002/tera.1420480504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThirty two infants referred for in‐patient genetics evaluation at the University of California at San Francisco, 1987–1992, were found to have a history of maternal cocaine use. Genetics reports and medical records were reviewed on all these infants to identify features distinctive for cocaine exposure. Among these 32 cases, 14 infants were exposed only to cocaine; 18 were exposed to alcohol and cocaine. The infants evaluated displayed a distinctive phenotype, consisting of neurologic irritability, large fontanels, prominent glabella, marked periorbital and eyelid edema, low nasal bridge with transverse crease, short nose, lateral soft tissue nasal buildup, and small toenails. Features consistent with the fetal alcohol syndrome appeared distinct and coexistent with the other described facial findings. Other severe abnormalities included cleft lip/palate, atypical facial cleft, abnormal BSER, intraventricular hemorrhages, arthrogryposes, and genitourinary abnormalities. Forty percent of the infants were born prematurely; 28% were small for gestational age; 43% showed head circumference values less than the 10th percentile. We conclude that these findings may be distinctive for a diagnosis of fetal cocaine syndrome; such findings should be further established by a future blinded prospective study of mothers and neonates.© 1993 Wiley‐Lis

ISSN:0040-3709    

DOI:10.1002/tera.1420480505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe concentrations of dopamine (DA), serotonin (5HT) and their metabolites were quantified in 5 brain areas of rats exposed to saline, cocaine (15 mg/kg b.i.d.), amitriptyline (10 mg/kg), or amfonelic acid (AFA, 1.5 mg/kg) throughout gestation. Male pups from 3 similarly treated dams were fostered to 2 surrogate dams. The process of breeding and rearing was repeated 4 times with new dams to build the groups to 4–12, since only one pup per litter was used for any one measurement. AFA was used to mimic the dopamine (DA) uptake blockade and stimulant properties of cocaine and amitriptyline was used to mimic the other pharmacological effects of cocaine. At postnatal days (PND)30, 60, and 180, one pup per litter was removed for HPLC analysis of monoamines. A second pup received 0.3 mg/kg haloperidol, catalepsy assessed after 1 hr, and the brain used for analysis. The cataleptic response to haloperidol was unaffected by any prenatal treatment. The striatum from PND 30 cocaine rats had decreased levels of DA without a decrease in DA metabolites. At PND 60 in cocaine exposed rats, DA and DOPAC concentrations were increased, and 5HT levels were decreased in the striatum. The amitriptyline‐exposed group exhibited decreased 5HT and 5‐HIAA levels in the striatum. The hypothalamus of the cocaine group had lower levels of 5‐HIAA, and other brain areas had a trend for lower levels of 5HT and 5‐HIAA. At PND 180, DOPAC was increased in the striatum and prefrontal cortex of the cocaine group. Haloperidol‐induced altered monoamine metabolism was unaffected by any prenatal treatment at any age. These data suggest that age‐related changes in the DA and 5HT neurotransmission systems occur in rats exposed prenatally to cocaine. However, the ability of the dopaminergic system to respond to a challenge by a DA receptor blocker is unaltered by these in utero treatments. © 1993 W

ISSN:0040-3709    

DOI:10.1002/tera.1420480506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe rat conceptus biotransforms N‐methyl‐N‐(7‐propoxynaph‐thalene‐2‐ethyl) hydroxylamine (QAB) in vitro to 7‐propoxynaphthalen‐2‐ylacetic acid (QAA) and six more (M1 to M6) metabolites. Thus far, M4 has been identified as N‐demethyl‐QAB and M6 as N‐desoxy‐QAB. We investigated which of these two metabolites might be involved in QAB‐embryotoxicity in vitro. Conceptuses were cultured from day 9.5 to 11.5 post‐coitum, and were exposed to N‐demethyl‐QAB or N‐desoxy‐QAB either in the culture medium or by microinjection directly into the amniotic cavity. When added to the culture medium, N‐demethyl‐QAB (No Observed Adverse Effect Level, NOAEL, for growth 122 μM and for differentiation 41 μM) was less active than QAB itself (NOAEL for growth and differentiation 12 μM). N‐desoxy‐QAB caused severe growth retardation and an impairment of differentiation at a concentration of 11 μM (NOAEL 3.6 μM). As regards causing anomalies, the NOAEL of N‐demethyl‐QAB (41 μM) was 10‐fold higher than that of QAB (NOAEL 3.9 μM) and that of N‐desoxy‐QAB (NOAEL 3.6 μM). At an intraamniotic concentration of 0.7 mM, N‐demethyl‐QAB caused no effects on growth and differentiation and no increase of anomalies was observed, whereas QAB and N‐desoxy‐QAB each elicited an increase in dysmorphogenic embryos at equimolar concentrations without affecting growth and differentiation. It is, therefore, concluded that N‐desoxy‐QAB, but not N‐demethyl‐QAB, could be a proximate dsymorphogen respons

ISSN:0040-3709    

DOI:10.1002/tera.1420480507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractTo describe the epidemiology of small intestinal atresia (SIA) in Atlanta, Georgia, from 1968 through 1989, we used the Metropolitan Atlanta Congenital Defects Program, an active, population‐based surveillance system for birth defects diagnosed during the first year of life. We identified 176 infants with SIA, a prevalence of 2.8 per 10,000 livebirths. Among black infants, the prevalence was 3.7 per 10,000 livebirths, significantly higher than the prevalence of 2.4 per 10,000 among white infants [relative risk (RR) = 1.6, 95% confidence interval (CI) = 1.1,2.1]. Nine infants were each one member of a unique pair of twins. The prevalence among twin infants was 7.3 per 10,000, significantly higher than the prevalence of 2.8 per 10,000 among singletons (RR = 2.7, 95% CI = 1.4,5.2). Forty‐nine percent of the infants had duodenal atresia, 36% had jejunal atresia, and 14% had ileal atresia. Two infants (1%) had atresia at an unspecified site in the small intestine. We grouped the infants by anatomic location of SIA into four categories: isolated SIA (53%), SIA with multiple unrelated defects (21%), sequences (16%), and syndromes (10%). We then compared the isolated and multiple unrelated defects groups by gender, race, maternal age, birth weight and one‐year mortality for each location of SIA. Among black infants the prevalence of isolated jejunal atresia was 1.4 per 10,000, significantly higher than the prevalence of 0.2 per 10,000 among white infants (RR = 6.3, 95% CI = 2.9, 13.5). The increased prevalence of these defects among twins was a particularly interesting finding. © 1993 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of

ISSN:0040-3709    

DOI:10.1002/tera.1420480508

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractPregnant Kun Ming strain mice were exposed to a total dose of 0, 0.1, 0.2, or 0.4 Gy from60Co γ‐rays from the 13th to the 18th days of gestation. An overall delay of the appearance of two physiologic markers (pinna detachment, eye opening) and the age of acquisition of four reflexes (surface righting, air righting, auditory startle, visual placing) was observed in offspring exposed to 0.2 or 0.4 Gy in utero. Postnatal growth retardation, shortened length of hanging time, inhibited exploratory activity in the hole board test (decreased number of head‐dipping), and hyperactivity in the open field test (shortened latency to leave the center area and increased number of squares entered) were also found among the offspring exposed to 0.2 Gy or more in utero. The results indicate that 0.1–0.2 Gy may represent a threshold range in mice for certain physiologic and behavioral effects resulting from continuous exposure to60Co γ‐rays on the 13th–18th days of gestation. © 1993 Wil

ISSN:0040-3709    

DOI:10.1002/tera.1420480509

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe SELH/Bc (SELH) inbred stock of mice has a high liability to the neural tube closure defect, exencephaly. All SELH embryos close their cranial neural tubes by an abnormal mechanism, lacking elevation and initiation of fusion in the posterior prosencephalon/anterior mesencephalon region. Most embryos complete closure of the cranial neural tube by extension of a more rostral site of fusion, but in 10–20% this process fails, and the embryos are subsequently exencephalic.In this study, transverse histological sections of the cranial neural folds of SELH embryos at the 3–5, 6–8, and 9–11 somite stages were compared to those of two strains with normal neural tube closure, ICR/Bc and LM/Bc. At all stages, consistent morphological differences were observed between SELH and the two normal strains. In 3–5 somite SELH embryos, the divergence of the folds from the neural groove is more angular, the folds are flatter, and their lateral tips appear “hooked” downward. In 6–8 somite SELH embryos, the lateral tips of the folds appear more elongated and in the prosencephalon they are less elevated than in the normal strains. The boundary between neuroepithelium and mesenchyme or surface ectoderm tends to be less clear than normal in SELH lateral tips. In 9–11 somite SELH embryos, divergence of the folds from the neural groove continues to be angular and the lateral folds are splayed horizontally. In addition, the lateral surface ectoderm is abnormally indented and the neuroepithelium/surface ectoderm boundary is more ventral and lateral in SELH than in ICR/Bc and LM/Bc.The hypothesis that the defect in SELH cranial neural folds might involve the cytoskeleton was tested using a fluorescent probe for filamentous actin in 7 somite SELH and ICR/Bc embryos. The actin staining pattern in SELH embryos was like that of normal ICR/Bc embryos, with a strongly staining apical concentration in the neuroepithelium. This suggests that there is no gross cytological abnormality within the neuroepithelium, but does not rule out more subtle defects, such as those involving cytoskeletal function. © 19

ISSN:0040-3709    

DOI:10.1002/tera.1420480510

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420480511

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY