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Biomedical subjects

D Blakeslee

Publications and source records attributed to D Blakeslee.

18 recordsLinked to original sources
PubMed1984

Excisional biopsy in the selective management of T1 glottic cancer: a three-year follow-up study.

Transoral excisional biopsy has been used in the evaluation and management of 103 T1 glottic cancers. A 3-year follow-up on these patients indicates that excisional biopsy unequivocally established the diagnosis and stage of the disease and that it is adequate treatment for micro and mini squamous cell cancers of the glottis in which the margins of excision are clear. Excisional biopsy with positive margins and larger T1 tumors establishes the absolute need for radiotherapy. Excisional biopsy is ideal for the diagnosis and management of verrucous carcinoma and spindle cell carcinoma. Recurrent/residual squamous cell carcinoma after radiotherapy should be explored by excisional biopsy which may be curative or will establish the need for partial or total laryngectomy. The appropriate use of excisional biopsy in the selective management of early T1 glottic cancers requires attention to detail by the surgeon and the pathologist and sound clinical judgment.

Biopsy↗
PubMed1981

Experimental porphyric neuropathy: a preliminary report.

An experimental model for the study of porphyric neuropathy is presented. Injection of either tetraphenyl-porphinesulfonate (TPPS), hematoporphyrin derivative (HpD), or delta-amino-levulinic acid (ALA) into mice resulted in markedly decreased motor nerve conduction velocity (MNCV). THe MNCV returned to normal within one week following the injection of large doses of ALA, and within three weeks following the injection of close to lethal doses of HpD, but there was no recovery of nerve function within 50 days following injection of substantially smaller doses of TPPS. Ultrastructural examination of motor nerves at various times following TPPS injection revealed the gradual development of structural abnormalities. Ultrastructural examination of the same nerves after a single dose of either ALA or HpD failed to demonstrate any abnormalities. The present observations call for precaution as to the use of TPPS as photosensitizer in human cancer treatment.

Aminolevulinic Acid↗
PubMed1979

Mitogen-induced changes in the fluorescence polarization of fluorescein in normal human lymphocytes: a membrane event?

The fluorescence polarization of human lymphocytes undergoing fluorescein fluorochromasia was measured in a system in which antifluorescein IgG was used to quench the extracellular emission of fluorescein leaked from the cells. The polarization values obtained from control cells were similar to those obtained by other investigators, as was the decrease in polarization in response to exposure to phytohemagglutinin or concanavalin A. However, the changes in polarization resulting from mitogen stimulation depended on the amount of antibody used, which suggests an increased or altered permeability of the plasma membrane to fluorescein efflux rather than a cytoplasmic reorganization.

Antibodies↗
PubMed1978

Isolation of a factor with toxohormone properties from mouse tumor cells in culture.

A small molecular weight factor with potent toxohormone activity was recovered from the serum-free culture supernatant of mouse MBQA fibrosarcoma cells. The factor depressed plasma-bound iron levels in mice and inhibited cell-free protein synthesis in microgram doses. Preliminary characterizations suggest that the active material is a small peptide.

Animals↗
PubMed1976

Immunofluorescence using dichlorotriazinylaminofluorescein (DTAF). I. Preparation and fractionation of labelled IgG.

Dichlorotriazinylaminofluorescein (DTAF), the product of the reaction of aminofluorescein with cyanuric chloride, is an effective reagent for conjugating fluorescein to immunnoglobulins. DTAF has absorption and emission properties nearly identical to fluoresceinisothiocyanate (FITC) and DTAF and FITC-labelled antibodies are similar in terms of preparation and specificity of immlnofluorescence. However, DTAF is superior to FITC with regard to cost, purity and stability. Also, DTAF-labelled rabbit IgG conjugates can by quickly and efficientyly fractionated by simple ammonium sulfate precipitation procedures to yield preparations free of both over- and under-conjugated material. In addition, over-conjugated protein can be readily removed from DTAF:IgG conjugates by appropriate adjustment of pH and temperature.

Animals↗
PubMed1976

The fluorescein-antifluorescein quenching system as a model for assaying changes in antibody function.

A rapid, simple and inexpensive procedure is presented for utilizing the fluorescein-antifluorescein quenching reaction as a model system to monitor and evaluate changes in antibody function brought about by conjugation and modification procedures. Experiments showing 1) the gradual loss of antigen-binding activity during dinitrophenylation, 2) the partial loss and subsequent recovery of activity during the reversible blocking of amino groups by citraconylation and 3) the quantitative release of bound fluorescein during guanidine denaturation were performed to demonstrate the versatility of the model.

Animals↗
PubMed1976

Rapid adsorption of a foetal calf serum component by mammalian cells in culture. A potential source of artifacts in studies of antisera to cell-specific antigens.

Injection of CBA mice the either mitogen-stimulated (LPS or con A) CBA lymphocytes which had been cultured for 3 days in the presence of foetal calf serum (FCS) led to the production of antisera which reacted strongly with virtually all types of mammalian cells, including human, whether normal or malignant, provided they had been cultured in FCS-containing media. Reactivity was detected by sensitive immunological assays such as complement-dependent cytoxocity using rabbit complement (but not using guinea-pig complement), or EA-rosette inhibition of Fc receptor-bearing cells. The antisera did not react with fresh normal lymphoid cells or ascites tumour cells; however, these same cell populations became fully susceptible to the cytotoxic effects of the antisera after as little as 4 h incubation at 37 degrees in the presence of FCS. Cells incubated without FCS or with FCS at 0 degrees were not affected. The antisera reacted with FCS to form a single band on Ouchterlony double-diffusion plates. On immunoelectrophoresis the reactive antigen appeared to migrate in the alpha-globulin region of serum proteins. These observations suggest that FCS may be a source of potentially serious misinterpretations in immunological studies of cell-associated antigens using antisera produced by the injection of cells grown in FCS-containing cultures. Examples of artifcats arising from the use of FCS in certain systems, e.g. the preparation of alloantisera using cultured tumour cells vs fresh non-cultured lymphoid cells, are described.

Adsorption↗