Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The function of the pituitary-gonadal axis in normal (immunocompetent) and nude (immunocompromised) mice, like that of other species, can be suppressed by luteinizing hormone-releasing hormone (LH-RH) agonists and antagonists administered by continuous release systems and, therefore, nude mice provide a valuable model for investigation of the effects of LH-RH analogues on growth of xenografts of human cancers. To extend our findings further, we treated male nude mice bearing xenografts of human prostate adenocarcinoma PC-82, for 42 days, with sustained release formulations (microcapsules or microgranules) of the agonist [D-Trp6]LH-RH, the antagonist [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Pal(3)3,D-Cit6,D-Ala10]LH- RH (SB-75), or the somatostatin analogue D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160). At necropsy, in mice given microcapsules releasing 25 micrograms/day of [D-Trp6]-LH-RH, tumor weight and volume were significantly decreased, compared with control mice, and weights of testes, ventral prostate, and seminal vesicles were also reduced in this group. In mice which received microgranules liberating 50 micrograms/day of antagonist SB-75, there was a greater decrease in tumor weight and volume than that produced by the agonist and a significant reduction in the weight of the testes and accessory sex organs. Histological parameters also demonstrated significant tumor inhibition, with the best results being obtained by treatment with the antagonist SB-75. The tumor inhibition induced by SB-75 was demonstrated to be due to decreased cellular proliferation, with enhanced cellular death (i.e., apoptosis) of the PC-82 cells. Microcapsules releasing 50 micrograms/day of RC-160 decreased tumor weight and volume by 23% and 28%, respectively, but this reduction was not significant. Serum levels of testosterone were decreased by 90% in mice given the LH-RH agonist and by 94% in response to the antagonist SB-75. Serum levels of prostate-specific antigen were significantly lower in mice treated with LH-RH analogues, with the antagonist SB-75 causing a greater reduction. A ratio of prostate-specific antigen to tumor weight suggests that levels of serum prostate-specific antigen may be correlated with tumor mass. Using sensitive multipoint micromethods, one class of binding sites for LH-RH, with a dissociation constant of 7.8 +/- 1.2 nM and a maximal binding capacity of 126.4 +/- 23.1 fmol/mg protein, was found in the control tumors. Tumors from mice treated with either LH-RH agonist or antagonist, but not somatostatin analogue RC-160, showed a significant reduction in maximal binding capacity for LH-RH, compared to control tumors.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Sustained release formulations of luteinizing hormone-releasing hormone antagonist SB-75 inhibit proliferation and enhance apoptotic cell death of human prostate carcinoma (PC-82) in male nude mice. 156 23

A better understanding is needed of the role of pre-analytical factors if prostate-specific antigen (PSA) is to be reliably used as a tumor marker. Reports on the analytical performance of TANDEM-R PSA (Hybritech, Inc., San Diego, CA) differ considerably with respect to detection limit and imprecision, differences that might be due (e.g.) to the use of different control matrices, to between-batch variations in reagent composition, or to nonrobustness of the assay. During nine months we determined PSA in 986 serum samples from 728 male urology patients and 54 samples from women (25 assay runs). As controls we used two serum pools with low PSA concentration and two widely used commercial controls. The within-assay CV for patients' samples was similar to that found with the commercial controls: 2.6% to 3.4% in the upper part of the normal reference interval. Precision was worse at lower concentrations (CVs 5-10% at about 0.5 micrograms/L). Imprecision tended to be higher at the end of runs. Assay drift for 100-tube runs was -4%. PSA was stable at -20 degrees C during six months. Neither the polyester polymer in SST tubes nor a hemolysate had any detectable effect on PSA values. Clinical analysis of the first 322 patients and all patients with PSA less than or equal to 0.20 micrograms/L highlighted the requirements for strict adherence to sampling instructions and to stringent quality control also at low analyte concentrations (analyte-free sera and sera with PSA concentrations 0.2-0.5 micrograms/L). Values with TANDEM-R PSA and IRMA-Count PSA (Diagnostic Products Corp., Los Angeles, CA) correlated well with no difference in detection limit or with samples from women. Within-assay precision was better with IRMA-Count PSA in the upper part of the normal reference interval and above. The designs of the two assays were compared in a format that is generally applicable for immunoassay kits (NORDKEM kit group, unpublished), and subjective impressions were recorded.
 ...
PMID:Determination of prostate-specific antigen in serum by immunoradiometric assay. 168 45

A mucinous adenocarcinoma of the prostate is rate, and a doubtful diagnosis should be verified to determine that the tumor surely does arise from the prostate, since a mucinous adenocarcinoma arising from the gastrointestinal tract is not as rare and often metastasizes to the prostate. We herein report on a case of a mucinous adenocarcinoma of the prostate, the origin of which was proved to be the prostate by immunohistochemical staining for a prostate-specific antigen and prostate-specific acid phosphatase.
 ...
PMID:[A case of mucinous adenocarcinoma of the prostate]. 169 Aug 26

Serum prostate-specific antigen (PSA) levels were determined in four groups of patients with prostatic carcinoma: 230 untreated patients with adenocarcinoma of the prostate after careful clinical staging; in 102 patients with localized prostatic carcinoma who were treated by radical prostatectomy; in 183 patients after radiation therapy for adenocarcinoma of the prostate; and in 45 antiandrogen-treated patients with documented metastatic disease. Within each treatment modality PSA proved to be a powerful tool in predicting stage and prognosis of each patient. In the untreated group the PSA level was directly proportional to advancing clinical stage and Gleason score. The rate of increase of PSA in clinical stage A and B cancer patients suggested a doubling time of at least 2 years. In the group of patients who underwent radical prostatectomy, PSA correlated extremely well with the tumor volume and had a high predictive value for pelvic lymph node metastasis. No patient with pelvic lymph node metastasis achieved an undetectable PSA level following radical prostatectomy without adjunctive therapy. Both anti-androgen and radiation treatment were followed initially by dramatic falls in serum PSA concentrations, but the majority of patients soon experienced a reversal of this initial response, signifying early failure and again providing new information unavailable from any other source.
 ...
PMID:[The role of prostate-specific antigen in the diagnosis and treatment of prostatic adenocarcinoma]. 169 83

To evaluate the clinical and prognostic value of prostate-specific antigen (PSA) for the detection of tumor and tumor growth after therapy, 520 sera from 246 patients with prostatic carcinoma, 990 sera from patients with BPH, and 1,488 sera from patients with other urological diseases were analyzed. The values ranged from 0.1 to 1,828.9 ng/ml. 51% of all values were about 2.5 ng/ml, and 76.8% of all values about 10 ng/ml. The commercial recommendation for the cutoff values is 2.5 ng/ml (IBL, FRG). In patients with benign prostatic hypertrophy this cutoff means 61% false-positive results, which makes the test highly sensitive but unspecific. In prostatic carcinoma patients this borderline means a false-negative result in 9.75% (24 of 246). By determining the cutoff at 10 ng/ml in our series, a false-negative result appeared in 14.6%. Therefore a plea is made for the 10-ng/ml cutoff. In follow-up studies a marked decline in PSA values after transurethral resection or antiandrogen therapy (orchiectomy/Zoladex/ICI/flutamide, Essex). Generally, the greater the PSA levels the more advanced the stage of disease. These data suggest that PSA may be a useful adjuvant marker for monitoring tumor growth in patients with regionally confined tumor.
 ...
PMID:Prostate-specific antigen in prostatic carcinoma. 169 55

Twelve patients with primary mucinous adenocarcinoma of the prostate were included in a clinicopathologic study; criteria included a total tumor volume more than 25% mucinous and single or clustered tumor cells floating in mucin lakes. Patient ages were 57 to 81 years; tumor stages were C (three), D (five), and unknown (four). Bone was the most frequent metastatic site (usually osteoblastic), followed by lymph nodes and lungs. Serum levels of prostatic acid phosphatase and prostate-specific antigen were frequently elevated (five of 10 and three of three measured, respectively). All mucinous adenocarcinomas also contained other histologic patterns: microglandular (four), cribriform (three), comedo (two), solid (two), and hypernephroid (one). Mucinous components composed less than 50% of three tumors, 50% and 75% of six, and more than 75% of three. No tumor contained signet-ring cells. Immunoperoxidase staining was positive for prostatic acid phosphatase and prostate-specific antigen and negative for carcinoembryonic antigen. Treatment was radiation, estrogen, orchiectomy, or a combination. In two of four patients, serum prostatic acid phosphatase levels normalized after therapy. Seven patients died of disease (mean follow-up, 56 months), and five patients are alive with disease (mean, 32.2 months). The proportion of mucinous component did not affect prognosis.
 ...
PMID:Mucinous adenocarcinoma of the prostate: histochemical and immunohistochemical studies. 169 91

The serum prostate-specific antigen (PSA) of 58 men with benign prostatic hypertrophy (BPH) and 17 men with carcinoma of the prostate (CaP) was correlated with the weight of prostatic tissue resected at transurethral prostatectomy (TURP). A significant correlation was identified between the weight of resected BPH tissue and the serum PSA (p less than or equal to 0.001; r = 0.54). No such correlation was seen in the CaP patients. By arbitrarily dividing the serum PSA by the prostate weight, it was possible to devise an index. This index corrected PSA in relation to prostatic size and unlike PSA in isolation did not differ significantly between normal controls and those with BPH. The index in CaP was significantly greater than that of either controls or BPH (p less than or equal to 0.001). Furthermore the index of metastatic CaP (M1) was significantly higher than that of nonmetastatic disease (MO) (p = 0.05). The higher index found in CaP would seem to be related to the bulk metastatic tumor, either manifest or occult. Comparing the index of CaPs to that found in normal and benign disease (a constant) offers a possible means of estimating the extent of local and metastatic tumor mass.
 ...
PMID:Quantification of prostatic cancer metastatic disease using prostate-specific antigen. 169 96

The role of prostate-specific antigen (PSA), a sensitive tumor marker for cancer of the prostate, has yet to be defined in patients treated with radiotherapy. To evaluate this, PSA and acid phosphatase (AP) were measured prospectively in 110 sequential patients who presented with locoregional carcinoma of the prostate and in whom radiotherapy was to be definitive treatment. Therapy was divided into the following treatment groups: external-beam radiotherapy alone (EBRT), EBRT with brachytherapy (EBRT + B), and hormone therapy either pre-EBRT or post-EBRT (EBRT + H). All patients have been followed for 1 to 17 months and a total of 521 posttreatment PSA determinations have been made. In 91 of 110 patients (83%) PSA was elevated pretreatment and correlated with clinical stage and subsequent relapse. There was no association with Gleason grade, assigned treatment group, or lymph node involvement. Acid phosphatase was elevated in only 31% of the patients initially and had no predictive value in subsequent failure. Nine patients have developed local and/or distant recurrence. None of the patients who failed had their PSA return to normal whereas 74 of 101 (73%) of the remainder have done so. Levels of PSA that do not return to normal during follow-up probably indicate active disease, often without evidence of clinical relapse. The authors conclude that PSA is a useful tumor marker for monitoring response to radiotherapy and may be a predictor of eventual failure thus identifying patients eligible for early intervention therapy as and when it becomes available.
 ...
PMID:Prostate-specific antigen. Monitoring the response of carcinoma of the prostate to radiotherapy with a new tumor marker. 169 77

The isolation and purification of prostate-specific antigen (PSA) and the development of a radioimmunoassay for this antigen represent major advancements for the detection of adenocarcinoma of the prostate and the monitoring of response to therapy in patients with this disease. Both monoclonal and polyclonal assays for PSA are available. In attempts to correlate pathologic tumor stage and PSA levels, tumors of higher stage (pathologic stages C1, C2, D1, and D2) have been associated with elevated PSA levels. Increased PSA levels have also been found in patients with benign prostatic diseases (benign prostatic hypertrophy and prostatitis). PSA has been shown to be an excellent marker after radical prostatectomy and for monitoring of radiation therapy. Patients with a persistently elevated PSA level for more than 6 months postoperatively should be assessed for residual or recurrent local or systemic disease. Thus far, routine use of PSA testing as a mass screening modality for prostatic cancer has not been considered cost-effective.
 ...
PMID:Prostate-specific antigen testing in untreated and treated prostatic adenocarcinoma. 169 14

Serum prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) levels were measured in 70 patients with benign prostatic hypertrophy (BPH) and in 70 patients with prostatic cancer. PSA was increased above the cutoff level of 10 ng/ml in 13% of patients with BPH and in 87% of patients with prostatic cancer. In contrast, abnormal PAP levels were found in 14 and 76% of patients, respectively. We concluded that, due to its high specificity, PSA is a useful marker in the management of patients with prostatic carcinoma and that it surpasses PAP in this regard.
Tumour Biol 1990
PMID:Clinical usefulness of prostate-specific antigen and prostatic acid phosphatase in patients with prostatic cancer. 170 Aug 60


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>