Comprehensive Sclerotinia Stem Rot Screening of Soybean Germplasm Requires Multiple Isolates of Sclerotinia sclerotiorum.

Sclerotinia sclerotiorum population variability directly affects Sclerotinia stem rot (SSR) resistance breeding programs. In the north-central United States, however, soybean germplasm selection has often involved only a single isolate. Forty-four S. sclerotiorum isolates from Illinois, Michigan, Minnesota, Nebraska, Wisconsin, Poland, and across 11 different host species were evaluated for variation in isolate in vitro growth, in vitro oxalate production, and in planta aggressiveness on the susceptible soybean 'Williams 82'. Significant differences (P < 0.0001) were detected in isolate in planta aggressiveness, in vitro growth, and in vitro oxalate production. Furthermore, diverse isolate characteristics were observed within all hosts and locations of collection. Aggressiveness was not correlated to colony growth and was only weakly correlated (r = 0.26, P < 0.0001) to isolate oxalate production. In addition, the host or location of collection did not explain isolate aggressiveness. Isolate oxalic acid production, however, may be partially explained by the host (P < 0.05) and location (P < 0.01) of collection. Using a representative subset of nine S. sclerotiorum isolates and soybean genotypes exhibiting susceptible or resistant responses (determined using a single isolate), a significant interaction (P = 0.04) was detected between isolates and genotypes when SSR severity was evaluated. Our findings suggest that screening of S. sclerotiorum-resistant soybean germplasm should be performed with multiple isolates to account for the overall diversity of S. sclerotiorum isolates found throughout the soybean-growing regions of the United States.

Early-stage glottic cancer: importance of dose fractionation in radiation therapy.

The treatment results in 85 patients with T1N0M0 squamous cell carcinoma of the glottic larynx who were treated with primary radiation therapy were reviewed to analyze for local control. After a minimum follow-up period of 2 years, 13 patients had local recurrence of disease, which yielded a local control rate of 84.7%. Local control was then reassessed as a function of substages (T1a and T1b) and dose fractionation. No difference in local control was seen in T1a and T1b neoplasms. However, after undergoing standard once-a-day fractionation, patients treated with fractions of 200 cGy had a local control rate of 96%, while those receiving 180 cGy had a local control rate of 79% (P = .05). Mean total dose for each patient group was comparable, and the median number of days of treatment interruption was the same for both groups. These data corroborate the recent findings of other authors regarding the importance of fraction size in facilitating local control of early-stage glottic cancer.

Radiotherapy as an adjunct in the management of Merkel cell carcinoma.

Four patients with a diagnosis of Merkel cell carcinoma initially underwent surgery followed by radiotherapy. Recurrent disease prompted use of radiation in three cases. The three cases of recurrent disease illustrate the aggressiveness of Merkel cell carcinoma and also provide further documentation of the radiosensitivity of this tumor. Additionally, these cases suggest that surgery alone frequently is inadequate to achieve local control of disease.

Coexistence of myelodysplastic syndrome and untreated chronic lymphocytic leukemia with development of acute myeloid leukemia immediately after treatment of chronic lymphocytic leukemia.

A 72-year-old man originally seen for anemia and thrombocytopenia was determined to have chronic lymphocytic leukemia (CLL). Bone marrow examination at the time of CLL diagnosis revealed a small but significant population of atypical blasts. Cytogenetic analysis of the bone marrow aspirate disclosed chromosomal abnormalities (-7, +8) suggestive of a myelodysplastic syndrome. Shortly after treatment of the CLL, there was proliferation of the previously noted blast population, which cytochemical studies demonstrated to be of the myeloid series thus indicating acute myeloid leukemia superimposed on CLL. This report presents microscopic, cytogenetic, immunophenotypic, and cytochemical evidence to document the evolution of acute myeloid leukemia in the bone marrow of a patient with CLL after one course of chemotherapy.

N,N-dimethylformamide-induced synthesis of an anti-fibronectin reactive protein in cultured human colon carcinoma cells.

The cell surfaces of human colon cancer cells before and after exposure to N,N-dimethylformamide (DMF) were probed using radioiodination and immunofluorescent labeling techniques. Growth of the human colon carcinoma cell line HCT MOSER in DMF-supplemented culture medium resulted in monolayer culture growth and marked cell morphology alterations consisting of cellular flattening and elongation. Accompanying the morphology alterations were distinct changes in the cell surface protein composition as determined by 125I labeling and electrophoresis. The cell surface changes associated with growth of HCT MOSER cells in the presence of DMF were dependent upon time of exposure to DMF and DMF concentration. Furthermore, removal of DMF-treated HCT MOSER cells from DMF-containing growth medium caused reversion of both cell morphology and cell surface composition to a state comparable to that of cells not exposed to DMF. The HCT MOSER cell surface alterations produced by DMF included a reduction of radioiodinated surface proteins with molecular weights of 87,000, 120,000, and 180,000 and an increase of a 125I-labeled surface protein with a molecular weight of 200,000-250,000. Appearance of a surface protein of approximately 200,000 molecular weight and assumption of a fibroblast-like morphology by DMF-treated HCT MOSER cells suggested that this approximately 200,000 molecular weight material might be fibronectin. Immunofluorescent labeling with anti-human fibronectin showed that HCT MOSER cells grown in DMF did manifest an anti-fibronectin immunoreactive material that was only transiently associated with the cell surface before being released. DMF-treated HCT MOSER cultures continued to express surface carcinoembryonic antigen, indicating that the presence of material immunoreactive with anti-human fibronectin was not secondary to proliferation of a contaminating fibroblast population. The response of HCT MOSER cells to DMF paralleled in many ways that previously reported for methylcholanthrene-transformed AKR-2B (AKR-MCA) fibroblasts. However, unlike AKR-MCA cells, HCT MOSER cells did not exhibit an increase in 125I incorporation per microgram DNA as a function of time of exposure to DMF, which suggests that the surface protein with a molecular weight of approximately 200,000 induced by DMF was not retained on the cell surface.

Cell surface features associated with differentiation-induction of methylcholanthrene-transformed AKR-2B fibroblasts by N,N-dimethylformamide.

Methylcholanthrene-transformed AKR-2B mouse embryonal fibroblasts (AKR-MCA cells) were examined for cell surface alterations after growth in culture medium containing N,N-dimethylformamide (DMF) using the lactoperoxidase-glucose oxidase radioiodination procedure with subsequent electrophoresis. DMF has been shown to induce maturational changes in a variety of transformed cells in vitro and has been reported to produce a more normal phenotype when applied to cultured AKR-MCA cells. The electrophoretic profile of 125I-labeled surface proteins from AKR-MCA cells exhibited a prominent peak of labeled material with a molecular weight of approximately 85,000. After growth of AKR-MCA cells in medium containing DMF, the Mr 85,000 peak was substantially reduced, while there was a large increase in Mr 200,000 to 250,000 radioiodinated surface material. This cell surface labeling pattern was virtually identical to that of the nontransformed AKR-2B fibroblasts from which AKR-MCA cells were derived. The cell surface alterations observed upon exposure of AKR-MCA cells to DMF occurred as a function of time of growth in DMF and DMF concentration. Growth of AKR-MCA cells in DMF resulted in a steady increase in cell surface 125I incorporation up to the fourth day of exposure to DMF. At this time, the incorporation level was 22.9-fold greater than that for untreated AKR-MCA cells. Incorporation of radiolabel was decreased after the fifth and sixth days of AKR-MCA exposure to DMF. This trend was also manifested by AKR-2B fibroblasts grown in the presence of DMF. The data suggest that there was increased expression of the Mr 200,000 to 250,000 surface protein on both AKR-2B and AKR-MCA cells when grown in DMF. DMF also inhibited morphological transformation and the cell surface changes associated with transformation of AKR-2B cells by exogenous transforming growth factors.

Mitomycin C resistance in a human colon carcinoma cell line associated with cell surface protein alterations.

A human colon carcinoma cell line resistant to mitomycin C (MMC) was obtained by repeated exposure of a previously described sensitive parental line, HCT 116, to MMC in vitro. Xenografts grown from the MMC-resistant phenotype were not inhibited in MMC-treated animals, while MMC treatment produced growth inhibition in parental cell xenografts. The MMC-resistant phenotype exhibited a greater amount of a Mr 148,000 cell surface protein than did the parental line. The increase in this Mr 148,000 cell surface protein correlated positively with the degree of MMC resistance. Alkaline elution of filter-bound DNA from resistant cells exposed to MMC in vitro showed a decrease in DNA cross-link formation such that a 10-fold higher MMC concentration was required to produce similar cross-link formation in the resistant cell as compared to the parental cell. The development of MMC resistance was not associated with in vitro cross-resistance to other natural product cytotoxic drugs. This model for resistance to MMC will be useful in future studies to define the mechanisms for MMC action and resistance in human colon carcinoma cells.

Induction of plasma membrane alterations in AKR-2B mouse embryo fibroblasts by endogenous growth factors from malignant human cells.

AKR-2B mouse fibroblasts were treated with 50 micrograms/ml of crude transforming growth factor (TGF) of human origin. Cell surface proteins of treated cells were radioiodinated and compared to untreated cells at various times after the addition of TGF. Treated cells showed a severalfold increase (approximately 6-fold) in cell surface 125I incorporation relative to normal cells at 24 h. Electrophoretic comparison of treated and untreated cells showed large increases in the labelling of cell surface proteins of mol. wt. 50,000-90,000 from TGF-exposed cells between 10 and 24 h post treatment. By 48 h post treatment, the electrophoretic profiles of TGF-exposed cells had returned to a pattern similar to that of untreated cells. However, even after a 48 h exposure to TGF, the cells retained a transformed morphology indicating that the electrophoretic alterations were not simply due to the morphological transformation induced by TGF. The electrophoretic pattern of TGF-treated cells at 24 h post treatment was similar to that of AKR-2B cells permanently transformed by treatment with methylcholanthrene, but was clearly distinct from that induced by treatment of normal AKR-2B cells with epidermal growth factor (EGF). EGF induced an increase in a protein of mol. wt. 60,000 in the electrophoretic profiles taken 24 h post treatment. As with TGF, the appearance of electrophoretic profiles of EGF-treated cells returned to "normal" by 48 h. Again, these alterations did not appear to be dependent upon morphological changes since EGF-treated cells showed a morphological transformation similar to that of cells treated with TGF, and this was maintained throughout the 48 h experimental period.

Cell surface proteins and glycoproteins from biologically different human colon carcinoma cell lines.

Six cultured human colon cancer cell lines possessing different biological characteristics were enzymatically radiolabeled in situ with 125I and 3H, and the labeled cell surface proteins and glycoproteins were compared. The electrophoretic patterns of labeled cell surface material suggest correlations between biological properties and cell surface proteins. Highly aggressive cell lines (as assessed by in vitro parameters) had predominant peaks of 125I-labeled proteins between molecular weights 66,000 and 92,500. The major peak of radioiodinated material from the more indolent cell lines occurred between molecular weights 31,000 and 45,000. The profile of one 125I-labeled intermediately aggressive cell line was similar to the profiles of the more aggressive lines, whereas another intermediate line exhibited a profile different from those of both indolent and aggressive lines. Electrophoresis of tritiated material indicated that essentially all of the recovered labeled glycoprotein was of relatively high molecular weight (92,000-180,000) in the indolent lines, whereas the intermediate and highly aggressive lines had patterns with significant peaks between molecular weights 45,000 and 92,500.

Characterization of human colon carcinoma cell lines isolated from a single primary tumour.

The initiation of a cultured human colon carcinoma line on a feeder layer of confluent fibroblasts is described. Attempts to initiate cultures without fibroblast feeder layers were not successful. Two sub-lines (designated HCT C and HCT C Col) were isolated and weaned from cells growing on the surface of the feeder layer. The sub-lines had different morphologies, secreted different levels of carcinoembryonic antigen (CEA) into the medium of confluent cultures and had slightly different karyotypes. Both sub-lines grew in semi-solid medium and formed xenografts when injected s.c. into athymic nude mice. Analysis of radioiodinated cell membrane components indicated small, but significant differences between the sub-lines.

Initiation and characterization of cultures of human colonic carcinoma with different biological characteristics utilizing feeder layers of confluent fibroblasts.

The tissue culture of human colonic carcinoma with and without feeder layers of confluent C3H 10T1/2 mouse fibroblast was compared. In a series of 27 different tumor specimens, 21 long-term cultures (6 mos. or more) were obtained by utilizing feeder layers. Only 3 long-term cultures were obtained from the same set of specimens when feeder layers were not employed. Several of the long-term cultures were established as cell lines weaned from fibroblast feeder layers. These lines could be classified into 3 groups based upon their expression of several biological properties including tumorigenicity in nude mice, degree of differentiation of the tumors growing in nude mice, growth in semisolid medium, morphology in vitro and production of carcinoembryonic antigen in vitro.

Definition And Measurement Of Three Processes Of Imagery Representation: Exploratory Studies Of Verbally Stimulated Imagery.

Three sets of experiments lend support to the hypothesis that there are at least three processes of imagery: (1) figural, in which a quasi-visual or other sensory representation of an object is made; (2) symbolic in which an abstract concepts is illustrated or symbolized by some imaginal representation; and (3) mimetic, in which a human experience is given a complex imaginal representation involving both envisionment and enactment or miming. Two types of scales for measuring stylistic differences in these three, processes are presented in detail. One type of scale is drawn from subjects' ratings of the ease and speed with which images are aroused by concrete, abstract, or personal words respectively. The other type of scale is drawn from subjects' ratings of the vividness of images aroused by various phrases specifically written to tap one or other of the hypothesized imagery processes. Two experiments are described in which the three processes are differentially activated by instructions as well as by type of stimulus material. In both experiments the expected interaction effects (between instructions and type of material) are found with p <.001.

The interaction of N-acetylhexosaminidase with insolubilized concanavalin A.

The specific interaction between human N-acetylhexosaminidase and concanavalin A was evaluated with respect to temperature, time, pH and concentration of specific ligand in incubation mixtures containing the enzyme and insolubilized lectin. Elution of the enzyme from insolubilized concanavalin A is dependent on both temperature and concentration of alpha-methyl mannoside. Conditions for a high yield of the enzyme from chromatography on insolubilized concanavalin A are described.