Biomedical subjects
N L Block
Publications and source records attributed to N L Block.
Enhancement of hyperthermic toxicity by lonidamine in the Dunning R3327G rat prostatic adenocarcinoma.
Hyperthermia alone or with radiation is used therapeutically for localized solid tumors. Clinical experience shows that sustained tumor temperature exceeding 45 degrees C damages normal tissue. Any agent that enhances the effects of hyperthermia at or below this temperature may have clinical relevance. Lonidamine and hyperthermia were tested on the Dunning R3327G rat prostatic adenocarcinoma. Using colony-formation assays, cytotoxic effects of each agent alone and in combination were quantified. Lonidamine to 100 micrograms/ml was not significantly toxic, but in combination, it enhanced cytotoxicity. Survival patterns after fractionated hyperthermia revealed a rapid development and decay of thermotolerance. Measurement of cell-cycle progression following a single dose of hyperthermia revealed a reduction of S-phase cells, and subsequent accumulation in G1 over 24 hours. Combination treatment of tumor-bearing rats significantly reduced tumor growth rate when compared with individual agents. These results suggest a potential use of lonidamine in hyperthermic therapy of prostate tumors.
Detection of prostatic-inhibin-like peptide in the cytoplasm of LNCaP cells, a human prostatic adenocarcinoma cell line.
Prostatic inhibin peptide (PIP) is a 94-amino acid peptide involved in various cellular functions. The concentration of this peptide changes with prostatic pathophysiology suggesting a role in various disease conditions; present study was undertaken to investigate the presence of this peptide in two human prostatic cell lines: LNCaP and PC3 cells. The LNCaP cells showed an intense intracellular fluorescence pattern after staining with rabbit-anti-PIP antiserum and FITC conjugated goat antirabbit-IgG, while the PC3 cells did not exhibit any fluorescence. There was no alteration in the concentration of PIP in LNCaP cells with or without supplementation of steroids in culture medium. Immunoblot analysis indicates similarities between PIP from LNCaP cells and that from the human seminal plasma. Thus, present study demonstrates the presence of PIP in a human prostatic cell line, i.e., LNCaP cells. Its intracellular concentration is androgen independent, and has a close similarity with PIP isolated from the human seminal plasma.
Identification of the human seminal TRH-like peptide pGlu-Phe-Pro-NH2 in normal human prostate.
Human and rat prostate contain thyrotropin-releasing hormone immunoreactivity (iTRH) including TRH and an uncharged TRH-like peptide. Recently the uncharged TRH-like peptide pGlu-Phe-Pro-NH2 was purified from human semen. To determine whether this peptide was of prostatic origin, human and rat prostate extracts were analyzed by ion-exchange chromatography and reversed-phase HPLC. The predominant uncharged iTRH comigrated exactly with synthetic pGlu-Phe-Pro-NH2 on HPLC and had identical affinity to pGlu-Phe-Pro-NH2 in a TRH radioimmunoassay. We conclude that prostate is a source of this peptide in humans and rats. This amidated TRH-like peptide may play a role in human reproductive physiology.
Renal parenchyma-sparing surgery as conservative treatment of renal cell carcinoma.
OBJECTIVE: To evaluate the role of parenchyma-sparing surgery in patients with renal cell carcinoma (RCC). PATIENTS AND METHODS: Between 1965 and 1990, 34 patients with RCC underwent renal parenchyma-sparing surgery. There were 22 men and 12 women with a mean age of 62 years (range 40-89). Ten patients underwent enucleation (Group A), 15 partial nephrectomy (Group B), and nine a combination of procedures (Group C). Conservative surgery was performed in the presence of a normal contralateral unit in four patients (12%). RESULTS: Five patients developed local recurrence. Metastases appeared in six patients (18%) from 12 to 58 months post-operatively. Adequate renal function was obtained in 32 of the 34 patients. The mean follow-up for all patients was 64.6 months overall, 75.6 months for group A, 64.1 months for group B and 53.4 months for group C. The 3 and 5 year probabilities of survival for all patients were 77.8% and 69.5% respectively. The probabilities of 3 and 5 year survival were 80% for group A, 80% for group B and 71.4% and 57.1% for group C. CONCLUSION: Enucleation and partial nephrectomy are both viable options in the management of solitary or bilateral RCC, as there is no decline in effective tumour control and prognosis. Larger groups and longer follow-ups are needed to assess the role of renal parenchyma-sparing surgery more definitively.
Human prostatic inhibin suppresses tumor growth and inhibits clonogenic cell survival of a model prostatic adenocarcinoma, the Dunning R3327G rat tumor.
Prostatic inhibin (PI) is a M(r) 10,700 protein found in human seminal plasma and is secreted by the prostate. Recognition of alteration of PI levels in prostatic diseases prompted us to investigate its effect on an animal prostatic adenocarcinoma model, the Dunning R3327G rat tumor. PI not only inhibited in vitro growth of tumor cells but also suppressed tumor growth in vivo. A dose-dependent inhibition of both the clonogenic cell growth and rate of proliferation (DNA synthesis) was observed in tumor cell cultures incubated with purified PI. These inhibitory activities were similar in both androgen-dependent and androgen-independent Dunning tumor cell lines. A functional decapeptide of PI was also found to inhibit Dunning tumor cell colonies in a dose-dependent manner. Daily injection of purified PI into tumor-bearing rats suppressed the tumor growth. A 58% reduction in tumor weight and a 2-fold reduction in tumor growth rate were observed over a 15-day treatment period. Continued treatment with PI significantly suppressed the tumor growth rate by nearly 3-fold. These findings clearly demonstrate a potential application of PI for treating human prostatic adenocarcinoma.
Secretion of matrix metalloproteinases and their inhibitors (tissue inhibitor of metalloproteinases) by human prostate in explant cultures: reduced tissue inhibitor of metalloproteinase secretion by malignant tissues.
Unregulated secretion of matrix metalloproteinases (MMPs) or their endogenous protein inhibitors (tissue inhibitor of metalloproteinases, TIMPs) has been implicated in tumor invasion and metastasis. Species of MMPs and TIMPs secreted by epithelial cultures of normal, benign, and malignant prostate were identified and their levels were compared. Fragments of fresh tissue were cultured in a serum-free medium that supported the outgrowth of prostatic epithelial cells. Biochemical analysis of the conditioned media by gelatin zymography and enzyme assays showed that both normal and neoplastic tissues secreted latent and active forms of both M(r) 72,000 type IV collagenase (MMP-2) and M(r) 92,000 gelatinase (MMP-9). However, conditioned media from malignant prostate explants contained a higher proportion of the active form of MMP-2. Significant amounts of free TIMPs were secreted by normal juvenile and adult prostates, but they were either markedly reduced or not detectable in conditioned media from neoplastic tissues. These findings suggest that there is an imbalance of secretion between MMPs and TIMPs in prostatic carcinoma.
Flow cytometric analysis of DNA and nuclear protein in paraffin-embedded tissue.
Previously we described the simultaneous quantification of DNA and nuclear protein in unfixed tissue from solid tumors. The resultant 2 parameter flow cytometric analysis has several advantages over that of DNA alone. In this report, we describe a modification of the technique for the analysis of formalin-fixed paraffin-embedded tissue. Paraffin-embedded material was prepared by hydrating sections, incubating in 0.5% pepsin solution, washing, and resuspending in buffer containing nonionic detergent. The nuclei were then stained with fluorescein isothiocyanate and propidium iodide in the presence of ribonuclease. Several solid tumor tissue types have been analyzed, including breast, colon, kidney, and thymus. The best results were obtained when the initial pepsin treatment was for 1.5 h, instead of 0.5 h. Pepsin treatment for 1.5 h improved the CVs of both the DNA and nuclear protein parameters, and did not appear to reduce nuclear protein levels or to cause significant disintegration of nuclei. The DNA/nuclear protein histograms of unfixed and fixed, paraffin-embedded tissue were similar. Since tumor nuclei typically have higher protein levels than DNA-diploid nuclei, the technique reduces population overlapping and permits less subjective identification of DNA aneuploidy.
Recognition and reduction of artifacts from autolysis in paraffin-embedded tissue using DNA/nuclear protein flow cytometry.
Artifacts from autolysis can be a problem in retrospective flow-cytometric analyses of DNA content in paraffin-embedded tissues. Autolyzed tissue from rat liver, human liver, and rat spleen were stained for DNA and nuclear protein to determine if this technique would be useful in identifying partially degraded cells. After the tissue was deparaffinized and rehydrated, the nuclei were isolated using 0.5% pepsin. Propidium iodide (PI) and fluorescein isothiocyanate (FITC) were used to stain DNA and nuclear protein. When unfixed rat liver tissue was allowed to undergo autolysis at 4 degrees C for 24-48 h before fixation, there was a progressive broadening of the G1 and G2M DNA peaks and a slight increase in the average DNA contents of these peaks. Nuclei that stained more intensely with PI also stained more intensely with FITC. Similar results were obtained using human liver and rat spleen. Sometimes the increased PI staining resulted in a false aneuploid peak. The distinctive skewing of the DNA/nuclear protein histograms from autolysis was reduced by increasing the incubation of the tissue in 0.5% pepsin from 0.5 h to 1.5 h during the nuclei-isolation step. The DNA/nuclear protein method provides a means for identifying artifacts from autolysis, whereas the extended pepsin treatment provides a means for reducing these artifacts.
Expression of prostatic TRH-like peptides differs between species and between malignant and nonmalignant tissues.
Thyrotropin-releasing hormone-immunoreactive peptides (iTRH) were analyzed in normal rat and rabbit prostates and in human benign prostatic hyperplasia (BPH) and prostate cancer. Peptides were extracted from tissues, fractionated by anion and cation exchange chromatography, and analyzed by TRH radioimmunoassay. pGlu-Glu-Pro-NH2 predominated in rabbit, but accounted for only 10-15% of iTRH in rat and human BPH. Uncharged peptides predominated in rat and human prostate. Authentic TRH (pGlu-His-Pro-NH2) is not present in rabbit prostate, but may account for up to 25% of iTRH in rat and human prostate. iTRH was virtually absent in prostate cancer. These results demonstrate considerable heterogeneity in the expression of TRH-like peptides in the prostates of various animal species, and suggest decreased expression of these peptides in prostate cancer.
Malignant fibrous histiocytoma of spermatic cord.
Malignant fibrous histiocytoma occurs rarely in the genitourinary organs, and is exceptional in the spermatic cord. The prognosis of deep malignant fibrous histiocytoma not occurring in subcutaneous tissue or fascia is generally poor. We report a case, of malignant fibrous histiocytoma giant cell type, arising around the spermatic cord. The patient is alive without metastasis ten years after initial therapy. To our knowledge, this is the longest reported survivor of this disease. Radical inguinal orchiectomy along with wide en bloc local resection is the therapy of choice.
Mature testicular teratoma with vena caval invasion presenting as pulmonary embolism.
We report a case of mature testicular teratoma with invasion and thrombosis of the inferior vena cava that presented as recurrent pulmonary embolism. Treatment included radical orchiectomy, chemotherapeutic cytoreduction and, finally, resection of a massive retroperitoneal tumor with en bloc resection of the inferior vena cava using cardiopulmonary bypass and deep hypothermic circulatory arrest. Management is discussed and the literature is reviewed.
Isolation of a prostate carcinoma cell proliferation-inhibiting factor from human seminal plasma and its similarity to transforming growth factor beta.
Human seminal plasma (SP) has been known to contain both growth-inhibitory and -stimulatory factors. We attempted to identify a factor that inhibited DNA synthesis in some metastatic prostate cancer cell lines. The SP factor was sensitive to digestion by trypsin, but its activity increased after boiling or dialysis against 1 M acetic acid, by 3- to 4-fold. The SP factor was partially purified using a cation-exchange resin. Apparent molecular mass determination by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed it to be a M(r) 25,000 protein, and M(r) 13,000 after reduction. This protein strongly inhibited DNA synthesis in two metastatic androgen-independent human prostatic carcinoma cell lines (PC3 and DU145) and the Dunning R3327G rat prostatic adenocarcinoma. It was ineffective on androgen-dependent LNCaP cells. The proliferation-inhibiting activity of this SP protein was specifically and completely abolished by a neutralizing anti-transforming growth factor beta (TGF-beta) antiserum. Furthermore, immunoblot analysis using the anti-TGF-beta antiserum showed the similarity of this protein to TGF-beta. The maximum concentration of this protein in SP was 165 +/- 11.7 ng/ml (mean +/- SD), of which only one-fourth may be present in active form under normal conditions. Identification of a TGF-beta-like protein in SP might also explain the variety of growth and immune modulation properties of human SP.
Metastatic prostate cancer presenting as obstructive jaundice.
Metastatic cancer of the prostate, presenting with carcinomatous obstruction of the common bile duct as a cause of jaundice and abnormal liver function tests is very unusual. The literature suggests an association between abnormal liver function tests and poor survivability in those patients with liver parenchymal metastases. This case illustrates that patients with abnormal liver function tests on the basis of extrahepatic ductal obstruction may have a better prognosis than those with hepatic disease.
Small bowel perforation associated with intraperitoneal and extraperitoneal bladder perforation caused by stab wound to the penis.
We report an unusual case of small bowel and bladder perforation caused by a stab wound to the penis with preservation of intact corporeal penile bodies and urethra. Diagnosis of bladder perforation was made by the urethrogram and diagnosis of small bowel perforation was made by clinical signs even though the initial physical examination suggested neither of these conditions.
Zoladex versus orchiectomy in treatment of advanced prostate cancer: a randomized trial. Zoladex Prostate Study Group.
We report preliminary results for the first 164 patients enrolled in a multicenter study comparing the endocrine effects, efficacy, and safety of 3.6 mg of goserelin acetate (Zoladex) and orchiectomy in patients with Stage D2 prostate cancer. Eighty-one patients were randomly allocated to receive Zoladex and 83 to orchiectomy. The median follow-up time for all patients was two hundred ten days. Median serum levels of testosterone were reduced to castrate levels (less than 50 ng/dL) within four weeks in both groups and remained suppressed for up to sixty weeks. An objective response according to modified criteria of the National Prostatic Cancer Project was observed in 81 percent and 78 percent of patients in the Zoladex and orchiectomy groups, respectively. There were no statistically significant differences between treatment groups in the distributions of time to treatment failure or time to disease progression. The most commonly reported adverse events in both treatment groups were hot flashes, cancer-related pain, unspecified pain, and urinary symptoms. These results suggest that Zoladex may offer an alternative to orchiectomy in the treatment of advanced prostate cancer.
Aneuploidy of glandular epithelial cells in histologically normal prostate glands.
The percentage of aneuploidy in normal prostate glands from subjects 13-38 years old and 45-66 years old ranged from 0-78% and 0-63%, respectively. In contrast to adults, aneuploidy was absent in fetal and postnatal prostates. It is concluded that aneuploidy is a fundamental attribute of histologically normal adult prostate glands.
Interaction of irradiation and microwave-induced hyperthermia in the Dunning R3327G prostatic adenocarcinoma model.
The interaction of radiation and hyperthermia was systematically studied in the Dunning R3327G prostatic adenocarcinoma, the preeminent animal model for human prostatic cancer. Subcutaneous tumors (produced by injection of 10(7) cells) were treated when they had reached a volume of about 1 cm3, which occurred about 3 weeks after implantation. With the use of a randomized complete factorial design, four factors were examined. Each agent was used at one of three dose levels. For radiation, these were 5, 15, and 25 Gy; for hyperthermia, 42 degrees C for 15 minutes, 43 degrees C for 30 minutes, and 44 degrees C for 60 minutes. Two sequences (hyperthermia plus irradiation and irradiation plus hyperthermia) and five time delays between agents (0, 12, 24, 48, and 120 hours) were used. The growth delay (the time it took for the initial tumor volume to double) of subcutaneously implanted tumor served to quantitate treatment effect. Significant (P less than .05) statistical interactions were observed for several combinations of factors and individual factors. Hyperthermia plus irradiation was more effective than irradiation plus hyperthermia except at the delay time between treatments of 0 hours. Peak growth delay occurred when the time between treatments was 0-24 hours and depended on agent doses. Many combinations produced therapeutic synergy.