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D E Kenady

Publications and source records attributed to D E Kenady.

At least 73 records · Page 4Linked to original sources
PubMed1986

Programming for the DNA analysis of FCM data on an IBM microcomputer.

The analysis of data generated on a flow cytometer (FCM) is often performed on a computer obtained especially for dedicated use with the flow cytometer. This computer component can be expensive and also presents the FCM user with the added burden of mastering specialized programming language or of accepting the secret analytical processes of protected proprietary program routines. We believe that the evolution of more accurate and efficient FCM analyses that have the power to consider complex signal distributions can be assisted by the availability of analysis programs written in languages common to many users. DNA analysis routines written for a relatively inexpensive microcomputer (IBM PC/XT) in Basic and Pascal are described here. The routines can automatically process multiple FCM data files and can provide high-resolution graphic hardcopy. A foreground/background utilization is also described that allows the computer to be available for other uses in the laboratory.

Animals↗
PubMed1986

The effects of acute administration of cytotoxic anticancer agents on the capacity for subsequent hormonal responses in the mouse uterus.

The mouse uterus has been used as a model system with which to examine the interaction of anticancer agents with steroid hormone receptors and to evaluate the effect of a single exposure to a cytotoxic anticancer agent on the subsequent elicitation of the uterotrophic response to estradiol. The uterotrophic response was interpreted in terms of the induction of progesterone receptors, uterine weight gain and increased uterine DNA content. Evaluation of 34 cytotoxic agents selected for this study provided little evidence to substantiate the interaction of these agents with estrogen or progesterone receptors. Although prior treatment with certain cytotoxic agents partially inhibited the subsequent responses to estradiol, some capacity to respond to estradiol was always retained. The majority of cytotoxic agents had little impact on the capacity to respond to estradiol. Thus, in these studies where high sublethal concentrations of cytotoxic agents were administered prior to estradiol, there was no indication that the mechanisms regulating subsequent hormonal responses were compromised.

Animals↗
PubMed1986

Proliferation, esterase activity, and propidium iodide exclusion in urologic tumor cells after in vitro exposure to chemotherapeutic agents.

After exposing urological tumor cells to anticancer agents in vitro, cellular esterase activity and the ability to exclude propidium iodide (PI) were examined as dual indicators of functionality or "viability." High esterase activity/PI exclusion was observed in assays in which anticancer agents failed to inhibit cellular proliferation, while low esterase activity/PI exclusion was often observed when proliferation had been significantly inhibited. In a number of instances, exposure to anticancer agents did produce significant inhibition of proliferation without lowering viability. In this setting, the recovery of proliferative capacity could be demonstrated with several transitional cell carcinoma cell lines, and this recovery was always associated with high esterase activity/PI exclusion. When the proliferation of primary urological tumor preparations was inhibited by drug exposure, estimates of elevated viability were obtained in 27 per cent of the determinations. Thus, viability estimates may be an indicator of the potential for tumor-cell recovery from exposure to anticancer agents. Moreover, the potential for recovery may explain differences between the results of chemosensitivity testing and actual clinical events by reconciling clinical failures with elevated viabilities indicative of this potential.

Antineoplastic Agents↗
PubMed1986

Cancer of the paranasal sinuses.

Cancers of the paranasal sinuses, although rare, continue to cause the death of more than half of patients afflicted with them. The use of combined therapy (surgery and irradiation) has effected some improvement in control, particularly with better surgical and radiation techniques. Unfortunately, better results will not be obtained until earlier diagnoses can be achieved.

Adenocarcinoma↗
PubMed1986

Antagonism to estradiol in the mouse: reduced entry of receptors complexed with 4-hydroxytamoxifen into a Mg2+-soluble chromatin fraction.

Antagonism to estradiol has been examined in murine uteri. When tamoxifen was administered simultaneously with estradiol (0.05 microgram/mouse), it was able to act as an antagonist over the dosage range 0.05-50 micrograms/mouse. The metabolite 4-hydroxytamoxifen (4OH-tamoxifen) had high affinity for estrogen receptors and was a slightly better antagonist over the dosage range 0.005-1 microgram/mouse. After uteri were exposed to either [3H] estradiol or [3H]4OH-tamoxifen, receptors complexed with [3H] estradiol penetrated a chromatin region, which was released as the Mg2+-soluble chromatin fraction after DNAase I treatment more readily than receptors complexed with [3H]4OH-tamoxifen. [3H]4OH-tamoxifen-receptor complexes could not be driven into the Mg2+-soluble chromatin fraction by increasing the ligand concentration during translocation. Relative to [3H]estradiol, significantly more [3H]4OH-tamoxifen was observed to associate with uterine cells and to penetrate the nucleus so that neither restricted entry nor extranuclear partitioning could explain the failure of [3H]4OH-tamoxifen-receptor complexes to enter the Mg2+-soluble chromatin. Bleomycin, an agent that interrupts DNA continuity, did not interfere with the appearance of estrogen receptor activity in the Mg2+-soluble chromatin fraction. Preincubation of intact uteri in the presence of molybdate (20 mM) did inhibit the appearance of receptor activity in this chromatin fraction; however, this effect did not occur through inhibition of receptor activation, but, rather, through the lowering of receptor activity in all chromatin fractions. In the studies reported here, the chromatin positioning of estrogen receptors complexed with estradiol appeared to be distinct from the positioning of receptors complexed with 4OH-tamoxifen. These observations suggest an additional basis from which the mechanisms separating the actions of estrogen agonists and antagonists can be approached.

Animals↗
PubMed1985

Hydrodynamic characterizations of estrogen receptors complexed with [3H]-4-hydroxytamoxifen: evidence in support of contrasting receptor transitions mediated by different ligands.

Size-exclusion high-performance liquid chromatography was used to characterize the hydrodynamic molecular properties of estrogen receptors complexed with estradiol and the antiestrogen 4-hydroxytamoxifen. Cytoplasmic estrogen receptors complexed with [3H]-4-hydroxytamoxifen did not undergo reductions in hydrodynamic size after exposure to KCl or urea. Nuclear receptors complexed with 4-hydroxytamoxifen eluted as hydrodynamically larger molecules than nuclear receptors complexed with estradiol. Because identical hydrodynamic characterizations were obtained with the covalent ligand [3H]tamoxifen aziridine, these differences in chromatographic behavior are due to differences in ligand-mediated receptor properties and are not the result of ligand dissociation. When estrogen receptors, complexed with either [3H]estradiol or [3H]-4-hydroxytamoxifen, were exposed to trypsin, the receptors complexed with 4-hydroxytamoxifen eluted as larger hydrodynamic forms than receptors complexed with estradiol. These observations are interpreted to indicate that estradiol and 4-hydroxytamoxifen mediate contrasting transitions in the molecular orientation of estrogen receptors. The consequences of the transitions mediated by 4-hydroxytamoxifen appear to be that intermolecular associations become difficult to disrupt with KCl or urea and that the accessibility of trypsin-sensitive proteolytic sites becomes altered. Chromatin fractionation using DNase I and hypotonic Mg2+ solubilization identified a chromatin region that was less readily penetrated by receptors complexed with 4-hydroxytamoxifen than receptors complexed with estradiol.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Growth of urinary transitional cell carcinoma cell lines in agar, agarose and methyl cellulose.

Because in vitro cell growth of transitional cell carcinoma explants and cell lines often fail to adequately proliferate in semisolid media, we have examined the effect of agents used to make media semisolid (methyl cellulose, Bacto-agar, Sea Plaque agarose and Sea Prep 15/45 agarose) on the in vitro growth of 11 transitional cell carcinoma cell lines. The growth of human transitional cell carcinoma lines was supported such that agents permissive for growth ranked as follows: Sea Plaque agarose approximately Sea Prep agarose greater than methyl cellulose greater than Bacto-agar. These observations have important implications for the in vitro study of transitional cell carcinoma cell lines and are relevant to the development of improved chemosensitivity determinations for human transitional cell carcinoma.

Agar↗
PubMed1985

Esterase activity, exclusion of propidium iodide, and proliferation in tumor cells exposed to anticancer agents: phenomena relevant to chemosensitivity determinations.

Cellular esterase activity and the ability to exclude propidium iodide were examined after exposing tumor cells to anticancer agents. In general, esterase activity and the ability to exclude propidium iodide continued when cells proliferated and disappeared when proliferation was inhibited. However, with a number of preparations, drug exposure inhibited proliferation while esterase activity and propidium iodide exclusion persisted. These indications of persisting cell function or viability after drug exposure may be relevant to a potential for tumor cell recovery. When the viability of established cell lines progressively declined on days 4 and 7 following drug exposure, recovery did not occur. When proliferative recoveries occurred, viabilities remained elevated. Estimates of in vitro sensitivity by proliferation-related criteria were contrasted by persistent high viability estimates in 22% of the determinations performed with primary tumor cell preparations. The potential for recovery may explain the disappointing ability of proliferative chemosensitivity assays to predict clinical sensitivity.

Antineoplastic Agents↗
PubMed1985

The surgical approach to primary malignant melanoma.

Surgical excision is the only curative treatment for malignant melanoma. Excisional biopsy of the suspected lesion allows for adequate tissue diagnosis and microstaging and does not alter ten year survival periods. Wide local excision with a resection margin of 3 centimeters is recommended for all but the most superficial (less than 0.76 millimeters) lesions. Nodal and systemic metastases and long term survival are unaffected by the size of the resection margin. The role of prophylactic lymphadenectomy for Stage I melanoma remains controversial. The results of both prospective and retrospective studies have demonstrated an improved survival after prophylactic lymphadenectomy for patients with intermediate thickness (0.76 to 3.9 millimeters or Clark's level III to IV, or both) lesions. Patients with ulcerated lesions and lesions in the BANS distribution, even when superficial, might benefit from elective lymphadenectomy. At least quarterly follow-up examination is recommended for those patients who undergo wide excision alone. Therapeutic lymphadenectomy is indicated for the treatment of Stage II melanoma. The results of ongoing prospective randomized studies will clarify the role of fascia removal, resection margins and prophylactic lymphadenectomy in the treatment of malignant melanoma.

Biopsy↗
PubMed1985

Steroid receptor analysis by size-exclusion liquid chromatography: considerations for the clinical laboratory.

Steroid receptor activity can be more quickly estimated by size-exclusion chromatography than by conventional analysis on sucrose gradients, and profiles of receptor activity are better resolved. Here we discuss several factors affecting this form of analysis in clinical laboratories. The composition of the elution buffer influences steroid receptor elution and recovery: high ionic strength, neutral pH, and the presence of dimethylformamide are important. Of the TSK-SW (Beckman) size-exclusion chromatographic columns we considered, the TSK-G2000SW column appeared to be the most appropriate. "Reference" elution profiles are presented for several marker proteins and estrogen receptor forms generated under different sample-treatment conditions. In examining the sensitivity of receptor analyses by this method, we used fresh rodent preparations, a commercial receptor reference (Estrocept), and human tumor material obtained by needle biopsy. We also compared frozen and lyophilized receptor preparations with fresh ones.

Animals↗
PubMed1984

VisiCalc and VisiPlot software routines and the analysis of data routinely encountered in steroid biochemistry.

The use of VisiCalc and VisiPlot software routines for performing calculations and graphing of data commonly encountered in steroid biochemistry is described. These software routines have utility and are relatively easy to use, requiring little or no programming experience. Use of these routines is demonstrated in terms of data processing associated with chromatography of receptor preparations and equilibrium binding analyses. The execution of these software routines is rapid and can result in a considerable savings of time and personnel. These and other generically similar software routines should have the greatest utility in laboratories where the experimental design is subject to on-going change.

Animals↗
PubMed1984

Management of abdominal wounds.

The three phases of wound healing are discussed, along with placement of incisions, choice of suture, and suture techniques. Good suture technique and the proper use of suture material can improve the current percentages of patients who experience abdominal wound dehiscence and incisional hernias.

Abdomen↗
PubMed1984

Stability of doxorubicin in relation to chemosensitivity determinations: loss of lethality and retention of antiproliferative activity.

The chemical stability of doxorubicin in a variety of tissue culture media has been studied by thin layer chromatography (TLC). In all the media examined, authentic doxorubicin was converted to a chemically distinct form as evidenced by the failure of this form to migrate on TLC plates. The rates of conversion were rapid enough (t 1/2 approximately equal to 3 hr) to be of consequence in chemosensitivity determinations, especially if working solutions of doxorubicin were to be routinely made and stored in tissue culture media. The addition of certain antioxidants to media did not prevent the conversion of authentic doxorubicin. However, doxorubicin was quite stable in distilled water. No single component of media was found to be responsible for the conversion of authentic doxorubicin, although arginine, histidine, tyrosine, NaHCO3, and Fe(NO3)3 could each generate a form of doxorubicin which did not migrate in TLC analysis. Purification of the nonmigrating form of doxorubicin demonstrated that in vitro conversion resulted in considerable loss of lethality while antiproliferative activity was retained. These observations provide possible explanations for the variability in chemosensitivity determinations and may explain some of the failures to predict clinical responsiveness.

Antioxidants↗
PubMed1984

Pancreas cancer.

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Carcinoma, Intraductal, Noninfiltrating↗
PubMed1983

Properties of anticancer agents relevant to in vitro determinations of human tumor cell sensitivity.

The physical properties of 59 anticancer agents have been examined with respect to solubility in tissue culture media, binding to ultrafiltration materials, and molecular absorbance and fluorescence behavior. Methods for dissolving these agents, which are compatible with in vitro sensitivity testing of human tumor cells to anticancer agents, are reported in this paper. The potential for anticancer agent binding to cellulose nitrate/cellulose acetate and teflon membrane ultrafilters was documented, and quantitation of these anticancer agents based upon absorbance and fluorescence spectroscopy was performed. Post-filtration quantitation of anticancer agents was found to be a reliable method for determining the actual drug concentrations available in tumor cell sensitivity testing in vitro. The properties documented herein are pharmacologically relevant parameters related to in vitro determinations of human tumor cell sensitivity to anticancer agents.

Antineoplastic Agents↗
PubMed1983

The proliferation of human tumor cell lines in the presence of different agars, agaroses, and methyl cellulose.

Human tumor cell lines, derived from cancers of the colon, ovary, and cervix, were grown in liquid tissue culture media and media made semisolid with agar (Bacto + deoxycholate lactose agar), agarose [LE, ME, Sea Plaque and Sea Prep (15/45)], and methyl cellulose. The effects of each agent on overall cell proliferation and rate of overall cell proliferation were examined. The agents, used to make media semisolid, were observed to inhibit or, in some cases, enhance cell growth in a fashion that was characteristic of individual cell lines. These phenomena may be of consequence to the optimization of nutrient media for primary tumor cell preparations.

Agar↗
PubMed1983

The effect of different agars, agaroses and methyl cellulose on the in vitro proliferation of a human urinary transitional cell carcinoma cell line.

The effects of different agars (Bacto-agar and deoxycholate lactose agar), agaroses (LE, ME, Sea Plaque and Sea Prep 15/45) and methyl cellulose on the growth of a human tumor cell line, derived from a transitional cell carcinoma of the urinary bladder, were examined. The overall growth in the presence of agars and agarose was generally less than in liquid medium alone. In contrast, growth in the presence of methyl cellulose was significantly enhanced. Thus, methyl cellulose may be a useful agent for optimizing the proliferation of primary tissue cultures prepared from human transitional cell carcinomas.

Agar↗