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Biomedical subjects

S C Goel

Publications and source records attributed to S C Goel.

25 records · Page 2Linked to original sources
PubMed1976

Reinterpretation of the ultrastructure of cartilage matrix.

The epiphyseal cartilage from new-born mouse was treated with collagenase in two ways: either before fixation or after glutaraldehyde fixation. The electron dense granules of the matrix were not seen in the micrographs of cartilage treated with collagenase before fixation. It is concluded that collagen plays a definite role in the formation of the granules at the time of tissue fixation and that the granules are fixation artifacts.

Animals↗
PubMed1976

Effects of trypan blue on the development of the garden lizard, Calotes versicolor.

The eggs of Calotes versicolor were exposed to different concentrations of trypan blue around the time of appearance of limb buds. The treatment resulted in malformations of limbs, hemorrhages in various locations, microphthalmia, kinky tail, and retarded development and growth of the contained embryos. The proportion of affected embryos varied significantly from clutch to clutch, perhaps due to genetic variation. All treated embryos, including those apparently unaffected, had trypan blue in the blood circulation, but not in the amniotic cavity or extraembryonic celom. Trypan blue was seen in kidney, liver, and other organs in decreasing order of frequency and concentration. On histological examination a change in the mitotic and necrotic frequency of the cells was noticed as one of the early events. The initial necrosis was close to blood vessels. The protective role of yolk sac in trypan blue-induced teratogenesis is discussed and contrary to the widely held view it is concluded that the yolk sac appears to play no such significant role in Calotes. It is suggested that trypan blue directly affects Calotes embryos, perhaps by altering cell permeability.

Abnormalities, Drug-Induced↗
PubMed1976

The use of methyl green-pyronin staining after glutaraldehyde fixation and paraffin or araldite embedding.

Methyl green-pyronin staining has been used for localization of RNA and DNA in chick and mouse embryonic tissues and in insect larval salivary glands. Glutaraldehyde or tricholoracetic acid-lanthanum acetate (TCA-LA) was used as fixative and paraffin wax or Araldite was used as embedding medium. For good results the following are specially desirable: fixation with 2.5% glutaraldehyde, dehydration in alcohols for short time, and the use of fresh staining solutions. After TCA-LA fixation the final results are much less specific. The digestion with RNAse appears essential for the detection of RNA because pyronin does not seem to be entirely specific to RNA. The results show that glutaraldehyde a common fixative for electron microscopic work, is particularly suitable fixative for light microscopic cytochemical investigations if followed by methyl green-pyronin staining; furthermore, methyl green-pyronin staining after glutaraldehyde fixation can be carried out on Araldite sections.

Animals↗
PubMed1975

Electron microscopic studies on chick limb cartilage differentiated in tissue culture.

The hind limb-bud mesenchyme of chick embryos 4-4 1/2 days old was cultured in Eagle's Minimum Essential Medium supplemented with both horse serum and fresh chick embryo extract. Whereas no differences are seen at the light-microscope level, at the electron-microscope level the chondroblasts differentiated in tissue culture are noticeably different from those differentiated in vivo, particularly in the possession of some cytoplasmic fibrils and vacuoles. It is proposed that the secretion of the extracellular matrix alone is not sufficient to account for the pattern of cellular arrangement in a cartilaginous condensation.

Animals↗