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Biomedical subjects

D M Hyder

Publications and source records attributed to D M Hyder.

12 recordsLinked to original sources
PubMed1993

DNA determination in dysplastic nevi. A comparative study between flow cytometry and image analysis.

Dysplastic nevi (DN), described in 1978, have been associated with increased risk of melanoma, but the role of DN as precursors of melanoma is still controversial. Recent studies have shown that DN are very common in the general population, bringing into question this purported association. Numerous investigations have attempted to correlate the presence of DN in individuals with specific phenotypic and genotypic features, including the presence of abnormal DNA content. Because the occurrence of such abnormal DNA stemlines in neoplasms may be associated with malignant behavior, we studied 38 biopsies from 19 patients that histologically fulfilled criteria for DN in order to ascertain characteristics of DNA content. Nuclear suspensions made from paraffin-embedded tissue were evaluated by both flow cytometry and image analysis techniques. All cases demonstrated diploid populations by both DNA measurement methods. Our results contradict previous reports of aneuploid populations in these melanocytic lesions.

Adolescent↗
PubMed1992

Comparison of image analysis with flow cytometry for DNA content analysis in pigmented lesions of the skin.

The DNA ploidy of 85 melanocytic skin lesions was determined by flow cytometry (FCM) and interactive image analysis (IA) using nuclear extracts of paraffin-embedded tissue. Of the 85 lesions analyzed, 43 were malignant melanomas in different stages of evolution, 15 were dysplastic nevi, 11 were Spitz nevi, and 16 were other types of nevi. Some of the last had features of congenital nevi. Within the melanoma category, there was 42% aneuploidy by FCM versus 56% by IA. Of those melanomas aneuploid by FCM, all but one were aneuploid by IA. All dysplastic nevi, 10/11 Spitz nevi and 15/16 other nevi were diploid by both methods. One of the 16 nevi from the "other types" category was tetraploid by IA but diploid by FCM. A single Spitz nevus was tetraploid by FCM but diploid by image analysis. While our results suggest that interactive IA is potentially a more sensitive method than FCM for detecting aneuploidy in cutaneous pigmented lesions, it remains to be shown whether this will translate into better prognostic assessment of the biologic behavior of melanocytic neoplasms than provided by flow cytometric ploidy analysis.

Aneuploidy↗
PubMed1988

Ki-1 lymphomas in children.

Three male children, ages 8, 11, and 14 at presentation, with the recently described Ki-1 lymphomas are reported. All three had lymph node involvement. The lymphoma was classified as immunoblastic in two children, and mixed small and large cell in the third child. In histologic terms, sinusoid, paracortical, and diffuse lymph node involvement by lymphoma was evident in each case. Both cases of immunoblastic lymphoma were T11+, T10+, T9+, HLA/Dr+, Tac+, Ki-1+, LCA+, and EMA+, while the lage neoplastic cells of the other case were T11+, Ki-1+, and LCA+. In all three cases DNA analysis of immunoglobulin heavy and light chain genes as well as T-cell receptor beta- and gamma-chain genes showed only germline patterns. The patients were treated with multi-agent chemotherapy. Two are in complete remission at 13 and 16 months, while the third failed to achieve remission and is alive with disease 12 months after a diagnosis had been established.

Adolescent↗
PubMed1988

Rearrangement of immunoglobulin and T-cell receptor genes in Hodgkin's disease.

The precise cellular origin of the malignant cell population in Hodgkin's disease (HD) is unknown. Recent application of Southern blotting techniques to detect clonal rearrangements of immunoglobulin (Ig) and T-cell receptor (TCR) genes has yielded conflicting results. The authors report the detailed analysis of tumor tissue DNA obtained from 18 cases of HD using Ig and TCR gene probes. The distribution of HD subtypes was similar to that in other series. Samples were examined for rearrangement by means of multiple restriction enzymes with specific probes for the Ig heavy chain, Ig kappa, Ig lambda, TCR beta, and TCR gamma loci. Only germline bands were detected in all 18 cases with the Ig gene probes and in 15 of 18 cases with the TCR probes. In 2 cases blot analysis suggested a predominance of polyclonal (or oligoclonal) T cells. In 1 case monoclonal rearrangement of the TCR beta gene was detected. Based on the intensity of the rearrangement and the small percentage of Reed-Sternberg (R-S) cells in this case, the clonal population detected was most likely not the R-S cell itself. The data do not support the frequent occurrence of Ig or TCR monoclonal gene rearrangement in HD.

DNA, Neoplasm↗
PubMed1986

Leu-M1-positive small cell carcinoma.

A case of metastatic small cell carcinoma of the lung is reported; initially, on the basis of morphology, phenotyping with monoclonal antibodies, and cytochemistry, the carcinoma was interpreted as a hematopoietic neoplasm. Noncohesive blast-like cells observed in bone marrow and lymph node biopsy specimens stained with the monoclonal antibodies Leu-M1 and OKIa1 and were also positive for nonspecific esterase and acid phosphatase. Although these findings suggested a monocytic origin for the neoplastic cells, further analysis, including ultrastructural examination, disclosed metastatic small cell carcinoma. This case illustrates the need for caution in the interpretation of staining with monoclonal antibodies because of the potentially wide range of normal and abnormal cells and tissues that may react with monoclonal reagents.

Adult↗
PubMed1986

Storage and transportation of lymphoid tissue for immunophenotyping.

Immunoperoxidase staining of frozen sections is a cost-effective technic for immunophenotyping cells of lymphoid tissue. Because this procedure is not performed in many institutions, a simple method to transport fresh tissue to centers performing these studies is required. Tissues in saline at refrigerator temperature may be successfully transported. In addition, in order to minimize laboratory expenses, lymphoid tissue can be kept refrigerated in saline until permanent sections are examined and immunodiagnostic procedures become necessary. In this study reproducible immunophenotyping of 12 samples of lymphoid tissue stored up to seven days was achieved.

Antibodies, Monoclonal↗
PubMed1986

Utility of Leu M1 monoclonal antibody in the differential diagnosis of Hodgkin's disease.

We conducted a retrospective study of the utility of Leu M1 monoclonal antibody staining of paraffin-embedded tissue in the differential diagnosis of Hodgkin's disease (HD). Forty-two cases of HD of various histologic types and 33 cases of non-HD lymphomas and hyperplasias were stained with Leu M1 using the avidin-biotin-peroxidase complex technique. Varying numbers, but not all Reed-Sternberg (RS) and Hodgkin's cells in all 42 cases of HD, were Leu M1 positive. These cases included seven examples of interfollicular HD and nine cases of lymphocyte-predominance HD, eight of which were nodular. Four of five cases of immunologically proved T-cell lymphoma contained Leu M1-positive RS-like cells, and Leu M1-positive RS-like cells were noted in two of five cases of non-HD lymphoma that were not phenotyped but were morphologically consistent with T-cell lymphoma. We concluded that Leu M1 staining is an aid in the diagnosis of HD, but it cannot be used to differentiate HD from T-cell lymphoma containing RS-like cells.

Antibodies, Monoclonal↗
PubMed1985

Effect of various storage conditions on a fluorescence polarization immunoassay for tobramycin.

The effects of various storage conditions on the results of a fluorescence polarization immunoassay for tobramycin were studied. Two venous blood samples (150 mL each) were drawn one hour and six hours after a single intramuscular dose of tobramycin. From each of these samples, which represented peak (6 micrograms/mL) and trough (1 microgram/mL) concentrations, aliquots of whole blood and of serum were prepared and stored in both glass and polypropylene containers. Serum samples were stored at -20 degrees C and assayed for tobramycin at intervals of 1-372 days. Samples of serum and whole blood were stored at 4 and 25 degrees C and assayed on days 1, 3, and 7. Mean tobramycin concentrations over time and between-run coefficients of variation were calculated for each set of samples. There was no substantial variation in tobramycin concentrations over time. Significant differences between tobramycin concentrations were noted only for peak serum samples in glass versus plastic containers at -20 degrees C and for trough serum samples stored in glass at -20 degrees C versus 25 degrees C. However, these differences were small and are unlikely to be clinically important. Under the conditions tested, the results of a fluorescence polarization immunoassay for tobramycin do not appear to be affected by storage time, storage temperature, container material, or storage medium (whole blood versus serum).

Adult↗
PubMed1984

Stability of theophylline in human serum and whole blood.

The effect of various storage conditions on serum theophylline results using a fluorescence polarization immunoassay (FPI) method was studied. Two human subjects received sufficient oral theophylline to produce low and high therapeutic serum theophylline concentrations. Aliquots of venous whole blood (without anti-coagulant) and serum from each subject were sealed in polypropylene plastic and glass containers and stored at 4 degrees C and 25 degrees C. Additional aliquots of serum from each subject were stored in glass and polypropylene containers at -20 degrees C. FPI assays were performed on days 0 and 3 for room temperature serum samples, days 3 and 7 for refrigerated serum samples, and days 3, 7, 14, 28, 56, 168, and 336 for frozen serum samples. All whole blood samples were assayed on day 3 after removal of the clot. Some samples were tested using FPI for 1,3-dimethyluric acid, a metabolite of theophylline, and results from spiked samples and samples tested with high-pressure liquid chromatography were compared with FPI results to determine cross-reactivity of the metabolite. No appreciable change in the assayed theophylline values occurred under any storage temperature, nor was there any difference in results from samples stored in glass versus polypropylene containers. At a concentration of 20 micrograms/ml, 1,3-dimethyluric acid produced a cross-reactivity of 3.5% with the FPI system. The FPI method is not affected by storage of samples under the specified conditions over the time period studied.

Adult↗
PubMed1978

A new chromosome abnormality in idiopathic sideroblastic anemia: 46,XY,del11q23.

A new marker chromosome, deletion 11q23, was observed with the Giemsa banding technique in the bone marrow of a patient with idiopathic sideroblastic anemia. The abnormality was not detectable in the peripheral blood or with nonbanded chromosome studies. Nineteen of 40 cases of this disorder studied and reported to date had chromosomal aberrations, although the majority had only nonbanded karyotypes performed. This apparently high incidence of chromosomal defects and the finding in the present case indicate that more banded-karyotype analyses are needed to assess the presence of possible nonrandom cytogenetic changes in idiopathic sideroblastic anemia.

Anemia, Sideroblastic↗
PubMed1975

The tissue culture and morphology of human breast tumor cell line BOT-2.

A continuous human breast tumor cell line (BOT-2) was derived from an infiltrating duct carcinoma. The tumor cell line was grown as a monolayer in flasks, but the cells could be readily adapted to growth in roller cultures. These studies indicate that BOT-2 cells have a 16- to 18-hr doubling time and a modal chromosomal number of 63. The original BOT-2 cell culture has been in continuous cultivation for almost 2 years and has been passed 137 times. The BOT-2 cell line has been differentiated from HeLa cells by isoenzyme studies and chromosomal analysis.

Alkaline Phosphatase↗