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Biomedical subjects

B Salzgeber

Publications and source records attributed to B Salzgeber.

17 recordsLinked to original sources
PubMed1986

The differentiation of repeated epilation (Er/Er) mouse mutant skin in organ culture and in grafts.

The homozygous repeated epilation (Er/Er) mouse mutant dies at birth and shows a variety of malformations, one of which is a skin defect. The developmental abilities of skin fragments from these Er/Er mouse embryos were studied in organ culture and in grafts performed either under the renal capsule of young mouse hosts or under the skin of mouse fetuses. In organ culture, the skin fragments differentiated in accordance with their genetic origin. The most characteristic feature was the abnormally thickened spinous layer and the formation of numerous epidermal nodules in Er/Er skin pieces removed from 13- to 16-day-old embryos, and cultured for 4 to 6 days, whereas the normal skin showed a constant layered organization. As in normal skin, keratin fibers developed within 4 to 6 days of culture. However, in contrast to normal skin, where keratin sheaths developed all over the surface of the epidermis, the Er/Er skin exhibited keratin masses inside the nodules. Combinations of mutant Er/Er epidermis with normal dermis resulted in abnormal skin differentiation, with formation of nodules similar to those observed for unseparated Er/Er skin fragments, whereas the reciprocal combination (normal epidermis with Er/Er dermis) produced normal skin differentiation. Cornified layers developed in both types of explants. Grafts of Er/Er and, for comparison, of normal skin fragments under the renal capsule or under a fetus's skin showed that the development of Er/Er skin in a normal or Er/+ host was similar to that of a normal skin. Thus, if isolated from the mutant organism, and inserted into a normal environment, the skin recovered within 6 to 7 days after transplantation and then developed normally. Our experiments suggest that the abnormal skin development of the Er/Er mutant might be caused by environmental influences.

Animals↗
PubMed1984

Studies on "Repeated Epilation" mouse mutant embryos: II. Development of limb, tail, and skin defects.

The present paper reports the development of limbs, tail, and skin abnormalities in homozygous Repeated Epilation (Er/Er) mouse embryos. Defects can first be observed on day 13 and become fully expressed at 18-19 days of gestation (vaginal plug = day 1 of gestation). In 13-day-old embryos, the apical ectodermal ridge and some areas of the limb epidermis are unusually thickened. A similar hyperplasia affects the tail tip and the flank epidermis. Limb defects are located in the autopod. Both pairs of footplates are shortened and deformed; no separation occurs between the digits. Only the phalanges are involved; they may be joined together either by soft tissues or by cartilage. Hypophalangy affects the most distal phalanges. Nails are missing or poorly developed. At stage 13, the tail tip is bent over the dorsal side and becomes twisted; at later stages, the tail appears shortened. From the 14-day stage onwards, there is a progressive fusion between the limb, the body, and/or the tail epidermis. The embryological analysis of the abnormalities indicates that the thickened and rigid epidermis impedes the normal growth of the limb buds and of the tail. Our observations suggest that limb and tail defects observed in mice homozygous for the Repeated Epilation mutation may be secondary to primary changes occurring in the epidermis. Some malformations described in this paper closely resemble those observed in sm/sm (syndactylism) and pf (pupoid fetus) mouse embryos.

Animals↗
PubMed1983

Studies on "repeated epilation" mouse mutant embryos: I. Development of facial malformations.

Repeated Epilation Er/Er mouse embryos show severe facial malformations. The most obvious is an important decrease in prominence of facial features. The protuberance of the snout is reduced. The eyes, the mouth, the nares and the ears are modified. From 13.5 days onwards the lips begin to close, the joining proceeding from the lateral to the central part. The nares, eyelids, oral opening, and auditory ducts are in the course of closure from 14 days of pregnancy. This process is terminated at 15 days. At the microscopic level, disturbances begin to appear at 13 days. They are limited to the anterior part of the face. During the next few hours, they become more important. At 14 days, the maxillae are joined from the anterior extremity of the snout. The oral opening is thus closed. Then, an oral cavity of very reduced form and dimensions is formed. The tongue connects the nasal septum to the mandible. A general process of closure occurs between: nasal septum, maxillae, tongue, and palatal shelves. Extensive modifications result from the compression of all these areas, especially of the tongue and shelves which remain in vertical position. An atypical cleft palate is seen, due to the absence of shelf movement, impeded by the tongue and the joinings mentioned earlier. The compression increases at 15 and 16 days. However, complete epithelial fusions do not occur. In 18-day-old embryos, cystic malformations appear in the glosso muscular system.

Animals↗
PubMed1981

[Changes in the female gonads of the chick embryo after tamoxifen].

Tamoxifen has been given to Chick embryos between the 3rd and 7th day at doses of 0.2-2 mg/egg. It was non-toxic and strongly anti-estrogenic. The female gonads were modified in their development. The ovary showed dense medulla with numerous cords and a reduced cortex. The right gonad partially regressed and was "masculinized". Mullerian ducts normally regressed in tamoxifen-treated male embryos. These results suggest the physiological intervention of estrogen during the normal embryonic female development.

Animals↗
PubMed1976

[Genesis of malformations of the distal parts of chick embryo extremities (adactylia, hemimelia)].

Two series of experiments were carried out on chick embryos, stages 24 to 28 pairs of somites. (1) Denuded mesenchyme obtained from leg presumptive area previously treated with nitrogen mustard, was grafted into the right flank of embryos, stages 15 to 24 pairs of somites. (2) Conversely, denuded mesenchyme was implanted into the flank of nitrogen mustard-treated embryos. In most of the embryos, a supernumerary abnormal limb appeared; 58% of the legs produced in the first set of experiments had distal parts, whereas only 15% of the legs in the second set of experiments showed toes. Most of these legs had a hemimelic aspect or were reduced to stumps. This study demonstrates that deficiencies localised in the ectodermal apical part of the bud may be responsible for the stumpy limb defect.

Animals↗
PubMed1975

[The effect of nitrogen mustard on the incorporation of tritiated thymidine into chick embryo limb buds. Autoradiographic study].

Tritiated thymidine labelling has been performed during the 24 hours following the treatment of chick embryos with nitrogen mustard. The rate of incorporation into nuclei of control and treated limb buds varied with the stage of the embryo. In the case of the nitrogen mustard-treated limb buds, a marked inhibition of the incorporation has been observed in the mesenchyme and the apical cap. However, 18 and 24 hours after treatment, the rate of labelling in the apical cap was the same as that in the control.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Repeated epilation: a genetic epidermal syndrome in mice.

Repeated epilation is an autosomal semidominant mutation located on chromosome 4 of the house mouse. Heterozygotes for Er show irregular hairloss. Homozygotes die immediately after birth from acute respiratory distress and exhibit an hypoplastic epidermal syndrome associated with morphological modifications of the oral cavity and of the limbs.

Abnormalities, Multiple↗