摘要:

AbstractOchratoxin A is a toxic isocoumarin derivative produced byAspergillus ochraceusand severalPenicilliumspecies, which are storage fungi. Many kinds of agricultural commodities can be contaminated with ochratoxin A, which has been reported in both animal and human foods. Pure crystalline ochratoxin A was dissolved in 0.1 N sodium bicarbonate solution and given intraperitoneally to pregnant ICR‐derived mice at dose levels of 1.25 and 2.25 mg/kg on gestation days 15, 16, and 17 (day 0, day of insemination). Dams were allowed to deliver, and their litters were culled to eight pups. During postnatal development, selected pups were tested for surface righting (days 3–12), swimming (even days 6–20) and pivoting (days 7, 9, and 11). Statistically significant differences for all three tests indicated that a developmental delay had occurred. Brains from the tested offspring were examined by light microscopy; no treatment or dose‐related pathoanatomic alterations wer

ISSN:0040-3709    

DOI:10.1002/tera.1420270302

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

年代:1983

数据来源: WILEY

摘要:

AbstractIncomplete fission of the primordial cell mass is generally believed to be the cause of conjoined twinning. It may also explain the tendency towards increased symmetry in these twins. We report a case of the rostral duplication type of conjoined twins with an absence of symmetry; one twin had the asplenia syndrome, whereas the other twin was normal. Local environmental factors acting upon the organ anlage may explain the asymmetric development in these conjoined twins.

ISSN:0040-3709    

DOI:10.1002/tera.1420270303

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

年代:1983

数据来源: WILEY

摘要:

AbstractPregnant C57BL/6J mice were given a single intraperitoneal injection of either a teratogenic (2,400 μg Cd/kg), an intermediate (40 μg Cd/ kg) or a trace dose (0.66 μg Cd/kg) of cadmium chloride (CdCl2) on day 9 of gestation; each dose contained109CdCl2(20 μCi). The mice were euthanized at various times after Cd exposure, and the amount of Cd in the embryos was determined in a gamma counter. For all three doses a low, but similar, percentage of the dose rapidly entered the embryos; levels then decreased during the next 11 hours, only to rise again by 24 hours and continue to rise for the remainder of the pregnancy. When the Cd content was related to embryonic weight the Cd concentration was at its highest level after 1 hour and then decreased rapidly and continued to decrease for the rest of pregnancy.Autoradioraphic studies showed that the teratogenic dose of Cd entered all tissues of the embryos but was particularly localized in cells of the neural tube, limb buds, and gut. By 12 hours, cell damage was seen in the embryos but the affected cells were not necessarily the heavily labelled cells. In embryos exposed to the nonteratogenic dose the highest Cd accumulation was seen in the embryonic gut and limb bud ectoderm but all tissues showed a low level of labell

ISSN:0040-3709    

DOI:10.1002/tera.1420270304

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

年代:1983

数据来源: WILEY

摘要:

AbstractPregnant hamsters were exposed to acetonitrile by inhalation, ingestion, or ip injection during the early primitive streak stage of embryogenesis. Inhalation of 1,800 or 3,800 ppm acetonitrile for 60 min failed to induce malformations in the near‐term offspring whereas inhalation of 5,000 or 8,000 ppm acetonitrile was associated with production of severe axial skeletal (dysraphic) disorders. One fetus afflicted with extrathoracic ectopia cordis was recovered from a dam exposed to 8,000 ppm acetonitrile. An oral or ip dose of 100–400 mg/kg acetonitrile in hamsters of equivalent gestational age also caused malformations identical to those noted following inhalation exposure. Some dams exposed to the highest concentrations or doses of acetonitrile displayed overt signs of poisoning. Multiple injections of sodium thiosulfate antagonized the mortality and signs of intoxication associated with acetonitrile treatment. Offspring of thiosulfate‐treated hamsters exposed to acetonitrile failed to exhibit the marked teratogenic response that was associated with exposure to equivalent concentrations or doses of acetonitrile alone. Elevated concentrations of cyanide and thiocyanate were detected in all tissues studied at 2.5 hr after an oral or ip dose of acetonitrile. Cyanide was liberated when acetonitrile was incubated in vitro with hamster liver slices or NADPH‐fortified hepatic microsomal preparations. The results suggested that in vivo liberation of cyanide from acetonitrile was responsible for the production of

ISSN:0040-3709    

DOI:10.1002/tera.1420270305

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe teratogenicity of thalidomide in Wistar rats was investigated after a single maternal intravenous injection during the organogenetic period. Thalidomide was administered at 45 mg/kg in 0.5 ml dimethylformamide (DMF) on day 10, 11, or 12 of the pregnancy. Thalidomide induced skeletal deformities of thoracic ribs and of the spinal column in 33 and 56 percent of the fetuses upon maternal administration of the drug on day 11 or 12, respectively. As compared to the solvent (DMF) control, thalidomide caused two‐ to three‐fold higher skeletally malformed fetuses. Deformities of the eyeball in fetuses (ophthalmorrhexis and microphthalmia) were induced by the maternal administration of the drug on day 10 and 12. The solvent (DMF) failed to induce organ deformities. Thalidomide induced embryotoxicity (as measured by percent dead and resorbed fetuses), at a rate three to eight times higher than the DMF control and represented 11 to 24 percent of dead and resorbed fetuses in thalidomide treated groups as compared to three percent in the DMF control group. Mean fetal weight was significantly reduced after maternal administration of thalidomide on day 11 of pregnancy, as compared to the DMF control. These studies conclude that thalidomide is teratogenic and embryotoxic in rats, when administered intravenously at 45 mg/kg

ISSN:0040-3709    

DOI:10.1002/tera.1420270306

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

年代:1983

数据来源: WILEY

摘要:

AbstractTriamcinolone acetonide (TAC) is teratogenic in rats while cortisol has been reported as not teratogenic. The objective of this investigation was to determine whether this difference in teratogenicity could be due to a difference in the metabolism and distribution of the parent compound in the embryomaternal unit.3H‐TAC and14C‐cortisol were administered intramuscularly to pregnant rats on day 12 of gestation. These dams were killed at each of the following time points after injection: 0.5, 1, 3, 6 and 24 hr. Maternal plasma and embryos were analyzed by high performance liquid chromatography (HPLC) and liquid scintillation counting. The plasma concentration of parent TAC was significantly greater than that for parent cortisol at all time points. The plasma elimination half‐life for TAC, 86 min, was also calculated to be significantly longer than that for cortisol, 8 min. Furthermore, the percentage of total plasma radioactivity representing HPLC resolved TAC was much higher than that representing cortisol at all time points. The concentration of TAC in the embryos was significantly greater than for cortisol at all time points. The elimination half‐life for unchanged TAC in the embryos was 142 min compared to 22 min for cortisol. The percentage of total radioactivity in the embryos representing unchanged TAC was similar to that found in maternal plasma while the percentage of total radioactivity representing unchanged cortisol was much lower than that found in maternal plasma. These findings support the hypothesis that differences in the distribution and metabolism of the parent compound are a critical factor in determining the teratogenicity of that

ISSN:0040-3709    

DOI:10.1002/tera.1420270307

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe effects of mirex on growth, histology, and K+and Na+concentrations of the fetal lens are examined. Pregnant Long‐Evans rats were intubated with 6 mg/kg/day mirex in peanut oil on days 8–15 of gestation. Control dams received pure peanut oil. Fetuses were removed on days 18–21 and rated for extent of lens opacification and degree of edema. Lenses were removed, weighed, and assayed for K+and Na+. Selected eyes were examined histologically. Cataracts were found in 49.6% of live treated fetuses on day 20, and the incidence and severity of cataracts were both correlated with the degree of fetal edema. Lens weights were reduced in treated litters whether or not cataracts occurred, but the reduction in cataractous lenses was greater. Sodium tended to be elevated and K+reduced in lenses from treated fetuses, and the K+/Na+ratio was significantly reduced in all treated groups. Histologically, treated lenses had swollen fibers on day 18 and areas of apparent cell breakdown by day 20. The swollen lens fibers, reduced K+/Na+ratios and the correlation with edema suggest that fetal cataraots induced by mirex may be due to lens fiber cell breakdown subsequent to osmotic swe

ISSN:0040-3709    

DOI:10.1002/tera.1420270308

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

年代:1983

数据来源: WILEY

摘要:

AbstractMaternal determinants of oral clefts have been documented in studies of experimental animals but not of humans. We studied maternal and paternal influences on the well‐known differences in the incidence of oral clefts between Whites and Blacks in the United States. Using United States birth certificate data for 1973–1978, we compared the incidence of oral clefts in offspring of White‐White, Black‐Black, and White‐Black couples. Because oral clefts are underreported on birth certificates, we also compared oral clefts as a proportion of all defects reported for offspring of various combinations of parental races. After adjusting for fathers race, offspring of White mothers had a higher rate of cleft lip with or without palate (CLP) than those of Black mothers (odds ratio [OR] = 2.33, P<10−4) and a higher proportion of CLP in their reported defects (OR = 2.41, P<10−4). This maternal race effect did not apply to cleft palate (CP), and it persisted after adjusting for mother's age, parity, and education. However, after adjusting for mother's race, offspring of White fathers did not have a higher rate or proportion of CLP or CP than those of Black fathers. The study shows that the difference in the reported rates of CLP between Whites and Blacks is due to the effect of mother's race, whereas the difference in the reported rates of CP cannot be attributed to the independent effect of mother's or father's race. The study documents the existence of maternal determinants of

ISSN:0040-3709    

DOI:10.1002/tera.1420270309

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

年代:1983

数据来源: WILEY

摘要:

AbstractBirth defects incidence for infants born to residents of Shawinigan, Canada in 1966–1979 were significantly higher than in three comparison communities. Since there has been a vinyl chloride polymerization plant in this town since 1943 from which ten cases of angiosarcoma of the liver have been identified, this study explores the possible association between exposure to vinyl chloride monomer (VCM) in ambient air and the occurrence of birth defects in the community. The excess of birth defects fluctuated seasonally in a way that corresponded to changes in VCM concentration in the environment. Mothers who gave birth to malformed children were younger on average in Shawinigan than in the comparison communities. However, there was no excess of still‐births in Shawinigan. The excess in birth defects involved most organ systems, and variation in birth‐defect rates among school districts could not be accounted for by estimates of VCM in the atmosphere. The occupational and residential histories of parents who gave birth to malformed infants were compared with those of parents of normal infants. The two groups did not differ in occupational exposure or closeness of residence to the vinyl chloride polymerization plant. Some descriptive data from this study raised the hypothesis of an association between VCM in the air and birth defects in the exposed community, but as a whole, within the sample size available, such an association could not be substant

ISSN:0040-3709    

DOI:10.1002/tera.1420270310

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

年代:1983

数据来源: WILEY

摘要:

AbstractThis communication reports the sectioning and subsequent examination of 1‐mm freehand razor blade sections of the normal 35‐day ferret fetus; pregnancy in the ferret lasts for 42 days. Skeletal and other abnormalities obtained after maternal treatment with teratogens, such as trypan blue, mustine hydrochloride, and sodium salicylate are included for comparison with the nor

ISSN:0040-3709    

DOI:10.1002/tera.1420270311

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

年代:1983

数据来源: WILEY