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Biomedical subjects

S Brenner

Publications and source records attributed to S Brenner.

At least 379 records · Page 21Linked to original sources
PubMed1982

Keratinization index.

A method to decrease subjectivity in assessing hyperkeratosis by application of quantitative measurements is proposed. The proportion of the depth of the stratum corneum to that of the total epidermis was measured on stained sections of tissue and termed the keratinization index (K.I.). Determinations showed that the K.I. varied with anatomical regions and was greater in different types of ichthyosis than in normal samples. Two indices were assessed, namely, K.I. which describes the ratio of cornified layer to total epidermis measured to the tips of the dermal papillae, and K.I. measured to the bases of the rete ridges. These two indices reflect the contour of the dermo-epidermal junction.

Ankle↗
PubMed1982

Dermal vasculitis due to coumadin hypersensitivity.

A 65-year-old patient developed nonpruritic purpuric skin eruptions following 10 days of coumadin treatment. Skin biopsy revealed vasculitis and immunofluorescent studies demonstrated the presence of IgM and C3 deposits in the walls of the affected blood vessels. Rechallenge with coumadin was followed by reappearance of the skin eruptions. Indirect mast cell degranulation test and migration inhibiting factor test were positive in the presence of coumadin. These findings strongly suggest that the skin lesions were induced by an immunologic reaction to warfarin.

Aged↗
PubMed1982

Leishmanid.

Explore the source record for details and available documents.

Child↗
PubMed1981

Laser microsurgery in cell and developmental biology.

New applications of laser microbeam irradiation to cell and developmental biology include a new instrument with a tunable wavelength (217- to 800-nanometer) laser microbeam and a wide range of energies and exposure durations (down to 25 X 10(-12) second). Laser microbeams can be used for microirradiation of selected nucleolar genetic regions and for laser microdissection of mitotic and cytoplasmic organelles. They are also used to disrupt the developing neurosensory appendages of the cricket and the imaginal discs of Drosophila.

Animals↗
PubMed1981

Site-specific properties of Tn7 transposition into the E. coli chromosome.

A study has been made of the insertional properties of transposon Tn7, a 14 kilobase transposable element encoding resistances to trimethoprim, streptomycin and spectinomycin. It has previously been shown that Tn7 transposes at a low frequency and with low specificity into multiple sites in large transmissible plasmids. However, Tn7 transposes with extreme specificity and at high efficiency into the E. coli chromosome. In all cases we have studied, insertion of Tn7 into the chromosome has occurred at a unique site and with a unique orientation. A combination of genetic and biochemical techniques have been used to precisely locate this site on the E. coli chromosome to minute 82 on the linkage map between markers glmS and uncA. To investigate the nature of this highly specific transpositional event, a small region of the E. coli chromosome that includes the unique site, was cloned into the plasmid vector pBR322. Subsequently a lkb restriction fragment, including the Tn7 insertion site, was sub-cloned from this plasmid into the plasmid pACYC184. We show that Tn7 transposes into both these plasmid recombinants with the frequency and specificity characteristic of the E. coli chromosome.

Chromosome Mapping↗
PubMed1981

Kinetochore structure, duplication, and distribution in mammalian cells: analysis by human autoantibodies from scleroderma patients.

The specificity of the staining of CREST scleroderma patient serum was investigated by immunofluorescence and immunoelectron microscopy. The serum was found to stain the centromere region of mitotic chromosomes in many mammalian cell types by immunofluorescence. It also localized discrete spots in interphase nuclei which we have termed "presumptive kinetochores." The number of presumptive kinetochores per cell corresponds to the chromosome number in the cell lines observed. Use of the immunoperoxidase technique to localize the antisera on PtK2 cells at the electron microscopic level revealed the specificity of the sera for the trilaminar kinetochore disks on metaphase and anaphase chromosomes. Presumptive kinetochores in the interphase nuclei were also visible in the electron microscope as randomly arranged, darkly stained spheres averaging 0.22 micrometers in diameter. Preabsorption of the antisera was attended using microtubule protein, purified tubulin, actin, and microtubule-associated proteins. None of these proteins diminished the immunofluorescence staining of the sera, indicating that the antibody-specific antigen(s) is a previously unrecognized component of the kinetochore region. In some interphase cells observed by both immunofluorescence and immunoelectron microscopy, the presumptive kinetochores appeared as double rather than single spots. Analysis of results obtained using a microspectrophotometer to quantify DNA in individual cells double stained with scleroderma serum and the DNA fluorescent dye, propidium iodide, led to the conclusion that the presumptive kinetochores duplicate in G2 of the cell cycle.

Animals↗