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Biomedical subjects

G L Wright

Publications and source records attributed to G L Wright.

At least 91 records · Page 5Linked to original sources
PubMed1992

The detection of prostate specific antigen, MHS-5, and other markers in invasive prostate cancer and seminal vesicle.

Prostate specific antigen (PSA) is the most useful serum marker for following the disease status of prostate cancer patients after therapy. While PSA is felt to be an organ specific marker, lack of PSA expression in the seminal vesicles has not been adequately established. MHS-5 is a monoclonal antibody which recognizes an epitope on seminal vesicle specific antigen. Our objectives were to define PSA expression by the seminal vesicles, to determine whether MHS-5 could serve as an adjunct in the diagnosis of seminal vesicles invasion by carcinoma of the prostate, and to determine whether carcinoma, having invaded seminal vesicles would retain its expression of PSA and other prostate markers. Using an immunoperoxidase procedure, we studied thirteen seminal vesicles without histologic evidence of prostate cancer invasion and five seminal vesicles with locally invasive cancer. No seminal vesicles expressed PSA, whereas prostate cancer invading the seminal vesicles expressed PSA in all cases. MHS-5 expression was more variable. Only two of five cases of locally invasive tumor demonstrated seminal vesicles expression for MHS-5. Our findings further support the specificity of PSA. While MHS-5 may be helpful in delineating seminal vesicles in some instances, it is not a consistently reliable marker.

Antibodies, Monoclonal↗
PubMed1992

Two-site monoclonal antibody-based immunoradiometric assay for measuring prostate secretory protein in serum.

We developed a double-determinant immunoradiometric assay for measuring serum prostate secretory protein (PSP), using monoclonal antibodies (MAb) against two different epitopes: MAb PSP-19 was the capture antibody and MAb PSP-6 was the tracer antibody. Assay sensitivity was 0.1 microgram/L. Analytical recovery of PSP was 93.5-104.6%, whereas the intra- and interassay mean CVs were 4.2% and 6.9%, respectively. In 92 normal men, ages greater than 50 years, the mean PSP concentration was 5.7 micrograms/L, with 10 (10.9%) men having concentrations greater than 10 micrograms/L. In contrast, 20 of 49 (40.8%) patients with benign prostate hyperplasia (BPH; mean PSP concentration 9.4 micrograms/L) and 46 of 100 (46%) patients with prostate cancer (mean PSP concentration 22.2 micrograms/L) had PSP concentrations greater than 10 micrograms/L. Mean serum PSP concentrations of the BPH (P less than 0.05) and prostate cancer (P less than 0.01) groups were significantly different from those of age-matched normal men. In a small group of patients, serial PSP concentrations correlated with the clinical course during therapy. Thus, PSP may be a useful marker for evaluating patients with prostate cancer.

Antibodies, Monoclonal↗
PubMed1991

Comparative study of monoclonal antibodies TURP-27 and HNK-1: their relationship to neural cell adhesion molecules and prostate tumor-associated antigens.

The murine monoclonal antibodies TURP-27 and HNK-1 have been shown to detect antigens which are heavily expressed by benign prostatic hyperplasia and carcinoma of the prostate. Western blot analysis of prostate extracts showed that monoclonal antibodies TURP-27 and HNK-1 bound glycoproteins with molecular weights of 180,000, 140,000, 120,000, 100,000, 90,000, and 69,000. Studies have shown that the HNK-1 carbohydrate epitope may be involved in cell adhesion and that it is a component of several characterized adhesion proteins. TURP-27 was found to bind at least three of these adhesion proteins: neural cell adhesion molecules; myelin-associated glycoprotein; and a second myelin glycoprotein, P0. Western blot analysis of prostate extracts showed that an antineural cell adhesion molecule serum bound the Mr 180,000 and 140,000 proteins. Based on reciprocal blocking and chemical tests, it was determined that the TURP-27 and HNK-1 epitopes are not identical. These data imply that the TURP-27 epitope may be a variant of the HNK-1 epitope or that the two epitopes are closely linked and that the TURP-27 and HNK-1 epitopes on prostate cells are positioned on neural cell adhesion molecule-like proteins.

Antibodies, Monoclonal↗
PubMed1991

A novel prostate carcinoma-associated glycoprotein complex (PAC) recognized by monoclonal antibody TURP-27.

A prostate carcinoma-associated antigen recognized by MAb TURP-27 was characterized immunohistochemically and biochemically. TURP-27 antigen was found localized in the cell membrane and cytoplasm of the ductal epithelial cells of normal (10%), benign (75-100%) and malignant (20-100%) prostate cells. Fetal prostate tissues were also found to express the TURP-27 antigen, suggesting expression early in development. This antigen was not expressed by non-prostate tumors examined, but significant cross-reactivity was observed in myelinated nerves while minor cross-reactivity was seen in certain lymphocyte subsets, cells in the adrenal medulla and chief cells of stomach. Immunoblotting and biochemical data demonstrated that the TURP-27 antigen is a sialic-acid-containing glycoprotein complex with major molecular species in prostate tissues of 310-250, 180, 140, 115, 95-90, 69, and 40- to 35-kDa. Immunoblotting patterns similar to those observed for prostate tissues were also seen in CNS extracts with the exception of the 69 and 40- to 35-kDa proteins. This prostate carcinoma-associated sialoglycoprotein complex (PAC) recognized by MAb TURP-27 is likely to represent a novel tumor antigen expressed by prostate tumors.

Adenocarcinoma↗
PubMed1991

Monoclonal antibody PD41 recognizes an antigen restricted to prostate adenocarcinomas.

A monoclonal antibody (MAb) designated PD41 (IgG1k) was generated by hyperimmunizing BALB/c mice with a membrane preparation prepared from a moderately to poorly differentiated prostate carcinoma surgical specimen. The immunohistochemical reactivity of MAb PD41 was shown to be highly restricted to the ductal epithelia and secretions of prostate adenocarcinoma tissues. Sixty-five % of the prostate tumor specimens were stained with MAb PD41, whereas no staining of the fetal or benign prostate specimens was observed. PD41 reacted minimally with normal prostate tissues, with less than 1% of the epithelial cells staining. This MAb did not react with nonprostate carcinomas or to a variety of normal human tissues. Using both radioimmunoassay and immunofluorescent procedures, several cultured human tumor cell lines, human blood cells, and purified antigens to prostate-specific antigen and prostatic acid phosphatase also were found not to express the PD41 antigen. MAb PD41 also was shown to bind to the target antigen present in seminal plasma obtained from prostate carcinoma patients but not to seminal plasma from normal donors. Immunoblots of gel-separated components of prostate carcinoma tissue extracts indicate that the molecular weight of the proteins carrying the PD41 antigenic determinant can differ among individual tumors, ranging from Mr 90,000 to greater than 400,000. However, in seminal plasma from prostate cancer patients, the predominant component recognized by PD41 is the diffuse Mr greater than 400,000 band. It appears that this monoclonal antibody may recognize a prostate carcinoma-associated mucin-like antigen, which is preferentially expressed on prostate carcinomas, and therefore, may be a useful marker to distinguish benign prostate hyperplasia from prostate carcinoma.

Adenocarcinoma↗
PubMed1991

Immunohistochemical evaluation of seven monoclonal antibodies for differentiation of pleural mesothelioma from lung adenocarcinoma.

A panel of seven monoclonal antibodies including anti-vimentin, anti-keratin markers AE1/AE3 and EAB902, human milk fat globule (HMFG-2), B72.3, anti-carcinoembryonic antigen (CEA), and anti-Leu-M1 were used for an immunoperoxidase staining assay to determine their value in the differentiation of pleural mesothelioma from lung adenocarcinoma. Anti-vimentin positively identified 86% of the mesotheliomas and none of the adenocarcinomas. AE1/AE3, EAB902, and B72.3 reacted with a high percentage of both mesothelioma and adenocarcinoma specimens. With HMFG-2, both membrane and cytoplasmic staining was observed in 92% of the adenocarcinomas and in 14% of the mesotheliomas, whereas 26% of the mesotheliomas only exhibited membrane staining. Eighty percent of the adenocarcinomas and 8% of the mesothelioma tissues stained with anti-Leu-M1. Anti-CEA did not react with any of the 50 mesotheliomas tested but did react with 95% of the lung adenocarcinomas tested. From this study, it was concluded that anti-CEA and anti-Leu-M1 were the most effective of the seven tumor markers evaluated; and that 100% of the pleural mesothelioma tissues could be correctly differentiated from lung adenocarcinomas using a panel consisting of anti-vimentin, HMFG-2, anti-CEA and anti-Leu-M1 monoclonal antibodies.

Adenocarcinoma↗
PubMed1991

Prostate specific antigen levels after definitive irradiation for carcinoma of the prostate.

Prostate specific antigen (PSA) levels were determined in 78 patients judged clinically to be free of disease at intervals of 36 or more months (range 38 to 186 months, median 87 months) after completion of irradiation therapy by 125iodine implantation or external beam radiation. Of this select group of patients 38% had undetectable serum PSA levels (0.5 ng./ml. or less) and 38% had PSA levels that were within normal limits (4.0 ng./ml. or less). All stages and grades were represented. Undetectable PSA levels were only rarely found (3%) in patients with carcinoma of the prostate before treatment. In 24 of these 78 patients a negative biopsy of the irradiated prostate had been obtained 18 to 42 months after treatment. When the PSA level was drawn, which ranged from 7 to 16 years after treatment, an equal percentage of these biopsied patients had either an undetectable, normal or elevated level. Irradiation is able to decrease PSA to undetectable levels in some patients with prostatic carcinoma. Whether this reflects suppression of marker production alone or, more importantly, ablation of prostate cancer producing that marker remains to be determined.

Acid Phosphatase↗
PubMed1991

Hypercholesterolemia and changes of vascular contractile responses in experimentally uremic rats.

Arterial contractile responses were studied in experimentally uremic rats. The ligation of 75% of the terminal branches of the left renal artery, followed by contralateral nephrectomy induced a chronic renal failure, as evidenced by significantly higher BUN concentrations and an elevation in blood pressure. Uremic rats exhibited elevations in total and HDL cholesterol, increased triglyceride levels, and significantly lowered HDL/total cholesterol ratios compared to control groups: 1) untreated control, 2) experimental control receiving renal infarction without contralateral nephrectomy, and 3) two kidney, one clip (2K1C) model of hypertension. Plasma total cholesterol levels in uremic rats increased by 50% in the first week following final surgery and plateaued at approximately 100% above control levels during postoperative weeks 3 through 10. Plasma transaminase levels were similar among all of the groups of rats studied indicating no effects of surgery on hepatic function. The contractile responses of aortic rings from uremic rats to submaximal concentrations of serotonin and clonidine were significantly increased and decreased, respectively, whereas the contractile response to norepinephrine was not altered. The enhanced sensitivity to serotonin of aortic rings from uremic rats was abolished following disruption of the endothelium. Neither the alteration of aortic contractile properties nor changes in plasma BUN and cholesterol concentrations were observed in hypertensive 2K1C rats. However, there was a tendency for decreased acetylcholine-induced relaxation in aortic rings of uremic and 2K1C rats. No significant histological evidence of atherosclerosis was found in aortic tissues of uremic rats during the interval of study. These results indicate that hypercholesterolemia, hypertriglyceridemia, and altered vascular sensitivity to serotonin and clonidine are likely to be primary changes in the uremic rat and are not secondary to the development of blood pressure elevation or overt evidence of structural change in the vessels of this model.

Animals↗
PubMed1991

Hypertensive factor in different models of experimental hypertension.

A hypertensive factor (HF), isolated from rat erythrocytes, has been shown to stimulate in vitro calcium uptake in aortic rings and to elevate blood pressure when injected into normotensive rats. In the present study, we investigated tissue responsiveness to HF in spontaneously hypertensive rats (SHR), Wistar Kyoto rats (WKY), 2-kidney, 1-clip renovascular hypertensive rats and uninephrectomized rats that were given water or saline to drink or that were treated with DOCA and given water or saline to drink (DOCA-salt). Tissue responsiveness was determined by incubating aortic rings from the rats in the different groups with a constant amount of HF and measuring "lanthanum-resistant" calcium uptake. Tissue sensitivity to HF was greater in SHR than in WKY. In contrast, tissue sensitivity to HF was not enhanced in 2-kidney, 1-clip renovascular and DOCA-salt hypertensive rats relative to their appropriate controls. These results suggest that the increased tissue responsiveness to HF found in SHR is not universally associated with elevated blood pressure; increased tissue sensitivity seems to be a specific characteristic of genetic hypertension.

Animals↗
PubMed1990

Flow cytometric DNA analysis after immunoselection of bladder tumor cells with monoclonal antibody DU83.21.

Adequate preservation of neoplastic cells and the elimination of interference by inflammatory cells in measuring tumor cell DNA content represent two important objectives necessary for accurate flow cytometric analysis of bladder carcinomas. An experimental model consisting of a mixture of cultured bladder carcinoma cells (T24) and human buffy-coat (BC) cells was used to evaluate various preservatives and an anti-bladder carcinoma monoclonal antibody (MoAb), DU83.21, for separating inflammatory cells (BC cells) from T24 cells. A final concentration of 25% ethanol was found to be the most effective preservative of several tested. After incubation with the MoAb DU83.21 and propidium iodide (DNA stain), the T24 cells could be separated from the BC cells, permitting accurate DNA analysis of the tumor cells. Application of this system to specimens from bladder cancer patients enhanced the detection and DNA analysis of the tumor cell populations.

Aneuploidy↗
PubMed1990

Generation and characterization of monoclonal antibodies to prostate secretory protein.

Monoclonal antibodies (MAbs) were produced against a highly purified preparation of prostate secretory protein (PSP) isolated from normal seminal plasma. Fifteen antibodies were selected for further evaluation based on their strong reactivity and specificity for PSP. All the MAbs had a specificity for prostate epithelial cells and none reacted to any of a variety of normal tissues as determined by immunoperoxidase staining. Six of the MAbs were selected for further immunohistochemical evaluation based on their ability to recognize different antigenic determinants. Using competitive binding immunoassays, a variety of overlapping specificities were observed with at least 2 distinct epitopes identified. Although some staining variability was noted, the 6 antibodies, in general, gave the same pattern of tissue reactivity. Both the normal prostate and the benign prostate hyperplastic ductal epithelial cells stained intensely, with 78 to 100% and 50-100% of the cells staining, respectively. The number and often the staining intensity of the tumor cells decreased as the tumor became more undifferentiated. Approximately 40 to 100% and 15 to 70% of the tumor cells stained in the moderately-differentiated and well-differentiated carcinoma tissues, respectively, whereas either no staining was observed or less than 20% of the tumor cells stained in the poorly-differentiated and undifferentiated tumors. Most of the metastatic prostate tumors showed either no staining or scattered staining in a few cells (i.e., less than 20%).

Adenocarcinoma↗
PubMed1990

A method for separating bound versus unbound label during radioiodination.

An inexpensive, highly effective, and safe method for the removal of bound versus unbound label during radiolabeling of proteins is described. The technique employs the use of membrane ultrafiltration technology and returns in one step a highly reproducible product of quality superior to that attained by gel chromatography. Advantages of this technique are a reduction in the quantity of liquid and solid radioactive waste and a significant limitation of potentially harmful manipulation and exposure times.

Chromatography, Gel↗
PubMed1990

Radiolocalization of human prostate tumor in a mouse subrenal capsule model by monoclonal antibody TURP-27.

The subrenal capsule assay was used to determine if 125I-labeled anti-prostate monoclonal antibody TURP-27 could target human prostate tumor fragments implanted under the renal capsule of normal immunocompetent C57 BL/6 mice. Maximal binding and optimal tumor to non-tumor tissue ratios occurred within 24-48 hours postadministration of 125I-TURP-27. No significant localization was observed in mice bearing TURP-27 antigen-negative human colon tumor tissue implants or with an isotype-matched control monoclonal antibody. These preclinical data suggest that TURP-27 may have clinical application for imaging metastatic prostate tumors and further application in immunoconjugate and/or radiotherapy of prostate cancer.

Animals↗
PubMed1990

Immunohistochemical evaluation of the expression of prostate tumor-association markers in the nude mouse human prostate carcinoma heterotransplant lines PC-82, PC-EW, and PC-EG.

The biotin-avidin immunoperoxidase assay was used to evaluate the expression of several prostate carcinoma-associated markers in formalin-fixed paraffin-embedded tissue sections of three human prostate nude mouse heterotransplant lines PC-82, PC-EW, and PC-EG. In addition to monoclonal antibodies to PSA and PAP, monoclonal antibodies to five other potentially useful markers for prostate carcinomas (TURP-27, Leu-7, 7E11-C5, PSP-19, and PD41) were tested. Tissues from two or more transplant passages were evaluated. The human prostate target antigens were found to be expressed by one or more of the three heterotransplant lines. The PC-82 and PC-EW lines were the most efficient in terms of expression of multiple prostate carcinoma-associated markers and percentage of tumor cells positive for a given prostate antigen. The staining pattern of each marker, in terms of staining intensity, number of tumor cells stained, and staining location, i.e., membrane, cytoplasmic, or ductal secretions, was similar to what has been observed in tissue sections from human prostate carcinomas. The lack of an appropriate model for evaluating the preclinical potential of these Mabs (especially TURP-27, PSP-19, and PD41) makes the findings of this study of considerable importance, and suggests that these human prostate xenografts may be useful models for exploring the diagnostic and therapeutic potential of these anti-prostate carcinoma monoclonal antibodies.

Acid Phosphatase↗
PubMed1990

Dunning rat prostate tumors and cultured cell lines fail to express human prostate carcinoma-associated antigens.

The objective of this study was to determine if human prostate carcinoma-associated tumor markers were expressed by Dunning rat prostate carcinomas. Frozen and formalin-fixed paraffin-embedded tissues from 12 different sublines of Dunning tumors were evaluated for marker expression by immunoperoxidase staining by using a panel of 9 monoclonal antibodies, including antibodies against human PAP and PSA. None of the Dunning tumors were found to express any of the human prostate tumor markers. Both fixed and live immunofluorescent assays were performed on 5 cultured Dunning tumor cell lines, evaluated either as single cells or as monolayers. As with the Dunning tumor tissues, none of the cell cultures expressed any of the 9 human prostate tumor markers. The lack of antigen expression by the Dunning tumor tissues and cell lines suggests that these human prostate tumor markers are quite species specific. These results limit the use of the Dunning prostate tumors as models to explore the preclinical application of these human prostate carcinoma-associated monoclonal antibodies and their target antigens.

Acid Phosphatase↗
PubMed1990

Effect of dietary calcium on in vitro aortic tissue responsiveness to a hypertensive factor.

It has been proposed that calcium supplementation in the diet is associated with a reduction in blood pressure. In the present study, we investigated vascular tissue sensitivity to a hypertensive factor (HF) in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) fed a high calcium diet, a low calcium diet and a food restricted diet. HF, which has been isolated from erythrocytes, increases blood pressure when injected into normotensive rats and stimulates calcium uptake by aortic rings in vitro. Five-week-old rats were divided into the following groups: SHR and WKY fed a regular diet (1% calcium), SHR and WKY fed a high calcium diet (4% calcium), SHR and WKY fed a low calcium diet (0.02% calcium) and SHR and WKY fed a regular diet (1% calcium) in which food intake was restricted to 65% of ad libitum intake. Food intake, body weight, urine phosphate excretion and blood pressure development were followed for 8 weeks. At sacrifice, plasma levels of calcium and phosphate were determined. Tissue responsiveness to HF was calculated by incubating aortic rings from the rats in the different groups with HF and measuring lanthanum-resistant calcium uptake. A 4-fold increase in dietary calcium reduced blood pressure and tissue responsiveness to HF in SHR. Neither parameter was affected by the high calcium diet in WKY. The low calcium diet had no effect on either blood pressure or tissue responsiveness to HF in SHR or WKY. Restriction of food intake induced a reduction in blood pressure and in tissue responsiveness to HF in SHR. It did not affect the same parameters in WKY. The results suggest that the increased tissue responsiveness to HF in the SHR may be associated with high blood pressure.

Animals↗
PubMed1989

Phenotypic and cytogenetic characterization of a cell line derived from primary prostatic carcinoma.

A new cell line, PPC-I, has been established from a specimen obtained from a patient with a poorly differentiated adenocarcinoma of the prostate. This is the first line of its type derived from a primary prostatic tumor site. PPC-I cells have become immortalized in culture, exhibit transformation parameters including relaxed growth factor requirements and anchorage-independent growth, and are highly tumorigenic in nude mice. Cytogenetic studies by G-banding revealed a grossly abnormal karyotype, with a modal chromosome number of 84, multiple marker chromosomes including both homogeneously staining regions and double minutes and clonal loss of chromosomes 3, 5, 10, 15 and Y.

Aged↗