ISSN:0040-3709    

DOI:10.1002/tera.1420010302

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

年代:1968

数据来源: WILEY

摘要:

AbstractThe development of the sternum was studied in normal and thalidomide‐treated rat embryos and fetuses. Morphologically, the sternal abnormalities included: crowding of the sternocostal articulations, absence of sternebrae, “scrambled” sternebrae, paired sternebrae, torsion of the sternum, partially cleft sternums, and completely bifurcated sternums. These malformations were related to an abnormal rib pattern and to a delayed growth rate of the ribs and sternebral primordia. Histochemically, the distribution and relative amounts of glycogen, alkaline phosphatase, calcium, and ribonucleic acid were studied. In cartilage the degradation of glycogen and the activity of alkaline phosphatase were influenced by thalidomide. This resulted in increased storage of glycogen and a reduction or absence of alkaline phosphatase activity. These changes were reflected in the rate of deposition of the cartilage matrix, and were most notable at the hypertrophic cartilage stage. Calcification of the cartilage was delayed, indicating the retardation in matrix deposition. No changes were observed in the staining pattern of ribonucleic acid. The deposition and calcification of endochondral bone was delayed, possibly caused by the delay in chondrification rather than by a direct effect on the ossification mechanism. No changes were observed in the development of the intramembranous, subperiosteal

ISSN:0040-3709    

DOI:10.1002/tera.1420010303

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

年代:1968

数据来源: WILEY

摘要:

AbstractInfection of pregnant rats withCoxiella burnetiiproduced an inapparent disease, but nevertheless induced many resorptions and grave fetal alterations, especially of the eyes, such as cataract and degeneration of retina and optic nerve. Similar experimental and clinical results have been observed by ourselves and others following other inapparent infections. Further investigation of the role of such infections in the origin of prenatal problems thus seems warranted.

ISSN:0040-3709    

DOI:10.1002/tera.1420010304

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

年代:1968

数据来源: WILEY

摘要:

AbstractAn attempt was made to identify all malformations among the 190,236 births that occurred in Birmingham in the ten years 1950–59. This was done by examining (a) obstetric summaries completed either by hospital staff or, for domiciliary births, by midwives; and (b) notifications of stillbirths, certificates of cause of death, and necropsy reports of infants who died in the first two weeks. The number of malformed individuals found was 3637 (19.1 per 1000 births).A more complete ascertainment was achieved in respect of the 1950–54 births by following the children to the age of six years and searching hospital records, death registers, necropsy reports, and the City's Public Health and Education Departments' registers of the physically handicapped and of the mentally subnormal. By these methods 2527 malformed individuals in a population of 94,474 births were identified (26.7 per 1000). The malformation rate was higher for hospital births than for children born at home; the difference was due to selection of patients for hospital delivery and not to inferior recording of domiciliary births.Details of all malformations recorded are given in table 6 and in the appendix. The most frequent malformations, each with an incidence of at least one per 1000 births, were clubfoot, cardiac anomalies, anencephalus, spina bifida, clefts of lip and palate, Down's disease, hydrocephalus, and polydactyly. These accounted for three–fifths of the total. Combinations of several malformations in the same individual occurred much more frequently than if association between malformations were fortuitous. Apart from the well–known associations of cardiac malformations with Down's disease and clubfoot with spina bifida and anencephalus, the most frequent combinations noted were cardiac defects with clubfoot and with clefts of lip and palate, and clubfoot with hydronephrosis and with reduction deformities of the upp

ISSN:0040-3709    

DOI:10.1002/tera.1420010305

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

年代:1968

数据来源: WILEY

摘要:

AbstractThis survey of the development of a large number of virtually unselected human embryos from healthy women allowed us to establish more reliable standards of normal development with respect to crown‐rump length, body weight, and external form than those usually cited. Remarkable variation was noted with regard to the relation between clinical age and these attributes and thus it is concluded that crown‐rump length and body weight are more reliable indicators of the general state of development than clinically established age.Dead embryos occurred with a significantly greater frequency in women with a history of genital bleeding during pregnancy than in those without. Externally malformed embryos were found with increasing frequency with advancing developmental stage, with the maximum figure of 3.92% at horizons 19–23. Malformations observed included external defects such as exencephaly, cyclopia, myeloschisis, cleft lip, and several limb malformations. It is of considerable interest that the incidence of most of these defects was far higher than that observed in newborn in

ISSN:0040-3709    

DOI:10.1002/tera.1420010306

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

年代:1968

数据来源: WILEY

摘要:

AbstractAfter five days in organ culture, untreated fifteen‐day fetal mouse tails showed a gradient of decreasing developmental maturity from proximal to distal. Segments of the tail treated with 10 μg/ml 5‐fluorouracil (FU) for periods of one to eight hours showed a gradient of drug susceptibility increasing from proximal to distal. The extreme sensitivity of the distal third of the tail was illustrated by the fact that it was even affected by 1 minute exposure to the drug. Exogenous uracil (20 or 40 μg/ml) had no protective effect against the action of FU when administered with, before, or aft

ISSN:0040-3709    

DOI:10.1002/tera.1420010307

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

年代:1968

数据来源: WILEY

摘要:

AbstractSome aspects of tissue differentiation were studied in 13‐day rat embryos after vitamin A treatment of their mothers on days 10, 11, and 12 of gestation. Severely affected embryos showed extensive growth retardation. Inhibition of cell proliferation, assumed from a decreased rate of H3‐thymidine uptake, was found in the liver, loose mesenchyme of the cephalic region, posterior region of the palatine shelves, trigeminal nucleus, and in some areas of the skin. Other tissues investigated showed no inhibition.Development of the face in these embryos was characterized by the appearance of defects in the mesoderm of the maxillary process and in the oral epithelium. It is suggested that palatal and dental abnormalities of vitamin A‐treated embryos arise because of some initial changes in the epithelium, which subsequently lead to a disrupted epithelial‐mesodermal relation in this region, so essential for normal development.Some physicochemical properties of vitamin A, such as its high surface activity and its effect on membrane permeability, enable it to have widespread effects. Information about the importance of these phenomena in the developing embryo must await further elucidation of the mechanism of action of vitamin A in biological organisms in

ISSN:0040-3709    

DOI:10.1002/tera.1420010308

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

年代:1968

数据来源: WILEY

摘要:

AbstractThe toxic and teratogenic dose‐response relations of 5‐fluoro‐2‐deoxycytidine (FCdR) were tested in strain C57BL/6JHanFfm at stage VIII of pregnancy, in substrain C57BL/10JFfm‐+ldat stage IX, and in strain C57BL/10JFfm at stage XI. Attention was focused on three regions of the skeletal system: skull, vertebral column, and limbs. The nonteratogenic range was nearly the same in all groups; differences were due only to the broadness of teratogenic range. This range was rather narrow at stage VIII in strain C57BL/6JHanFfm and quite broad at stage XI in strain C57BL/10JFfm.Concerning teratogenicity, at stage VIII in strain C57BL/6JHanFfm there was a high amount of single regional defects in the vertebral column (VC) and multiple regional defects (m.r.d.) in the skull and VC; at stage IX in substrain C57BL/10JFfm‐+ldthere was again a high rate of single regional defects in the VC, which were substituted by m.r.d. in all three parts of skeleton at higher doses of FCdR. At stage XI in strain C57BL/10JFfm the teratogenic effects started with single regional defects in the VC and continued with m.r.d. in VC and limbs; at the highest dose (20 mg/kg) it changed to m.r.d. of the three main regions of skel

ISSN:0040-3709    

DOI:10.1002/tera.1420010309

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

年代:1968

数据来源: WILEY

摘要:

AbstractIt has previously been shown that mice of the C57BL/6J strain are more resistant to the cleft palate‐producing effect of 6‐aminonicotinamide when raised on Purina Lab Chow than when raised on Breeder Chow. No such difference was observed in the A/J strain. This effect of diet on resistance was present in the F1offspring of C57BL/6J females mated to A/J males but not in the offspring of the reciprocal cross. When the two types of F1females were backcrossed to A/J males the difference persisted only in the offspring of the F1females with C57BL/6J mothers, suggesting that the factor conferring resistance was transmitted through the cytoplasm. In the present study the cytoplasmically transmitted factor conferring resistance did not persist in the second backcross. Neither did it appear to be transmitted through the sp

ISSN:0040-3709    

DOI:10.1002/tera.1420010310

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

年代:1968

数据来源: WILEY

摘要:

AbstractSelection increased the heterozygous expression of Strong's luxoid gene (hindfoot polydactyly) in a high line (SH) and lowered it in a low line (SL). The realized heritability in the SH line was 0.142 ± 0.029; in the SL line, 0.159 ± 0.010. SH homozygotes showed as indirect responses increased hindfoot polydactyly, reduction of tibia and pubis, while SL homozygotes showed opposite responses for tibia and pubis. Selection in a PF subline for forefoot polydactyly in heterozygotes induced severe radial reduction as an indirect response in homozygotes. Selection increased the expression of radial duplication in a high line (SHH) and lowered it in a low line (SHL). The realized heritability in the SHH line was 0.110 ± 0.061; in the SHL line, 0.326 ± 0.180. In both lines heterozygous sibs of homozygotes with high or low radial expression were chosen for breeding since homozygotes rarely reproduce. In the SHH line heterozygotes with high expression and in the SHL line heterozygotes with low expression of polydactyly were preferred for mating. SHL homozygotes showed indirect responses in their hindlimbs similar to those observed in SL homozygotes while SHH homozygotes showed a less marked tendency to follow the SH pattern. These results suggest that the effects of Strong's luxoid gene on distal and proximal parts of the limb have a reciprocal inverse relat

ISSN:0040-3709    

DOI:10.1002/tera.1420010311

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

年代:1968

数据来源: WILEY