Growth regulation of prostatic stromal cells by prostate-specific antigen.

BACKGROUND: Prostate-specific antigen (PSA) is a serine protease that can cleave insulin-like growth factor-binding protein-3 (IGFBP3), thereby decreasing its affinity for insulin-like growth factor-I (IGF-I). Dissociation of the IGF-I-IGFBP3 complex renders IGF-I available to bind to its receptor and stimulates cellular proliferation. We evaluated the potential for PSA to modulate the effects of IGF-I and IGFBP3 on the proliferation of human benign prostatic hyperplasia (BPH)-derived fibromuscular stromal cells in primary cultures. METHODS: We cultured BPH-derived stromal cells for 48 hours in serum-free RPMI-1640 medium supplemented with 0.2% bovine serum albumin and studied the effects of IGF-I, IGFBP3, PSA, and ZnCl(2) at varying concentrations. Differences in cell growth between control and treated cultures were evaluated by use of Dunnett's test. Concentration-related trends were evaluated by linear regression of log-transformed concentrations of test reagents on BPH-derived stromal cell number responses. Statistical tests were two-sided. RESULTS: We observed a concentration-dependent proliferative response of BPH-derived stromal cells to IGF-I. IGFBP3 inhibited this response in a concentration-dependent fashion. IGFBP3 alone had no effect on stromal cell proliferation. When stromal cells were incubated with PSA alone or with PSA, IGF-I, and IGFBP3, an increase in stromal cell numbers that was dependent on PSA concentration was evident in both instances. Zinc, an endogenous inhibitor of PSA enzymatic activity, was able to attenuate the stimulatory effect of PSA at intraprostatic physiologic concentrations. CONCLUSIONS: These results are consistent with the idea that PSA can modulate in vitro interactions between IGF-I and IGFBP3 and suggest that PSA may play a role in the regulation of human prostatic fibromuscular cell growth.

Comparative antitumor effects of hormonal ablation, estrogen agonist, estrogen cytotoxic derivative, and antiestrogen in the PAIII rat prostatic adenocarcinoma.

The effects of hormonal ablation, estrogen, estrogen-derived cytotoxic agent, and estrogen antagonist therapies used clinically were evaluated on in vitro colony formation, in vivo growth, and lymphatic and pulmonary metastasis of the PAIII tumor. Ventral prostatic and seminal vesicle weights were evaluated in the same animals to assess androgen-related responses. Estradiol, estramustine phosphate, and testosterone had no effects on PAIII colony formation in vitro. Castration, hypophysectomy, estradiol benzoate, and estramustine phosphate treatment of PAIII-bearing Lobund Wistar rats produced significant (P less than 0.05) regression of male accessory sex organs. Of these treatments, only hypophysectomy had significant (P less than 0.05) inhibitory effects on primary PAIII growth and lymphatic and pulmonary metastasis. LY117018 [6-hydroxy-2-(p-hydroxyphenyl)benzo(b)thien-3-yl-p-2-(l-pyrrolidin yl)ethoxy phenyl ketone] has antiestrogenic activity but produces no significant agonist responses. LY117018 had no effect upon PAIII colony formation in vitro. Following s.c. implantation of PAIII cells, LY117018 (2.0, 10.0, or 20.0 mg/kg s.c.) had no effect on primary tumor growth in the tail. In vitro LY117018 administration produced marked antimetastatic effects. In a dose-dependent manner, LY117018 inhibited PAIII metastasis to the gluteal (97%) and iliac lymph nodes (88%) (P less than 0.05 for both). LY117018 also maximally inhibited pulmonary metastasis by 86% (P less than 0.05). Maximal regression of 42% for ventral prostatic and 35% for seminal vesicle weights were also seen after LY117018 administration (P less than 0.05 for both). Co-administration of estradiol benzoate had no antagonistic effect upon the antitumor responses produced by LY117018. The mechanism of action of LY117018 is not known. The failure of estradiol benzoate to affect PAIII growth and metastasis supports the contention that the responses to LY117018 are not attributable to simple antagonism of estrogen action. LY117018 may be exerting its antitumor effects through autocrine, paracrine, or endocrine mechanisms. LY117018 represents a class of agents with potential utility in treating metastatic cancer of the prostate.

Iodine 125 suture implants in the management of advanced tumors in the neck attached to the carotid artery.

Between 1975 and 1982, 38 patients with locally advanced head and neck cancer attached to the carotid artery underwent surgical excision followed by iodine 125 vicryl suture implant in the neck. Most patients had neck masses that were greater than 6 cm and stage IV disease without clinically evident distant metastases. Twelve patients had received no previous therapy while 26 underwent an implant for recurrent disease. The local control rate in the implant volume was 79%. The local and regional control rate in all head and neck sites was 53%. The mean survival was 11 months. The overall complication rate was 26%. There was no significant correlation of local control or complications with the minimum total dose, volume implanted, individual 125I seed strength, or total seed strength. In patients with large masses attached to the carotid artery, surgical resection followed by a 125I implant for residual disease is a viable alternative to resection of the carotid artery.

Evidence for biological action of the antiestrogens LY117018 and tamoxifen by different mechanisms.

The influence of LY117018 and tamoxifen on established uterotropic influence of estradiol was examined in immature ovariectomized rats. When LY117018 was introduced on the fourth day of estradiol treatment, it regressed the uterotropic effect of estradiol. However, tamoxifen did not attenuate estradiol activity under these conditions. Injection of estradiol, commencing on the fourth day of LY117018 treatment, elicited no increase in uterine weight, while tamoxifen caused substantial uterotropic action in the presence of established, continuous LY117018 treatment. The uterotropic influence of tamoxifen also occurred when it was administered concomitantly with LY117018, and a similar result was observed following the injection of 4-hydroxytamoxifen with LY117018. These observations demonstrate that LY117018 can block or regress uterotropic effects of estradiol, but it cannot antagonize the action of tamoxifen or its hydroxylated metabolite. This suggests that these antiestrogens might act at separate sites or by different molecular mechanisms.

Androgens lower prostaglandin E2 levels in neonatal mouse bulbourethral gland in in vitro cultures.

The neonatal mouse bulbourethral gland (BUG) in vitro culture model is useful to study hormone-induced genitourinary (GU) tract growth and differentiation. Like the prostate, the BUG is a derivative of the urogenital sinus and may have relevance to understanding growth processes involved in normal and pathological GU tract development. Previous studies have reported androgen-induced elevation of prostaglandin E2 (PgE2) levels in mouse GU tract in vivo. PgE2 has been proposed to mediate neonatal GU tract masculinization. In our studies, tissues were obtained from neonatal male mice and cultured in serum-free Dulbecco's Modified Eagle's Medium-Ham's F-12 Medium (1:1) supplemented with varying concentrations of androgen. PgE2 levels were measured by RIA in the medium, and tissue specimens were cultured for 7 days or less. During this period, androgens induced proliferation and glandular morphogenesis in the BUGs. In the absence of androgen, tissue and medium PgE2 levels increased over 7 days. Significant (P < 0.05) PgE2 increases over day 1 control values were observed from days 5-7 in tissues and on day 7 in media. During this same time period, androgen supplementation decreased PgE2 levels. Significant (P < 0.05) PgE2 decreases from day 1 cultures were observed from days 3-7 in tissues and on day 7 in media. PgE2 was decreased significantly (P < 0.05) by androgen compared to control values from days 3-7 in tissues and from days 5-7 in media. On day 7 of culture, PgE2 levels were significantly (P < 0.05) inhibited by androgen in a concentration-dependent fashion in tissues and media. Maximal androgen-induced inhibition of PgE2 levels was 96% and 99% in tissues and media, respectively. Although the addition of indomethacin to control cultures markedly inhibited PgE2 production, BUG morphology was unaffected. In addition, the morphology of androgen-stimulated BUGs does not appear to be affected by the addition of exogenous PgE2. We conclude that although androgens induce development and decrease PgE2 levels, PgE2 does not appear to play a major role in in vitro BUG postnatal growth and morphogenesis. The BUG in vitro culture model may mimic growth and morphogenetic processes occurring in the human GU tract. Further understanding of the role of steroid hormones and PG metabolism may yield additional insight into developmental and proliferative GU tract disorders.

Clinical studies with In-111 BLEDTA, a tumor-imaging conjugate of bleomycin with a bifunctional chelating agent.

Indium-111 BLEDTA, a bleomycin analog containing an EDTA group, was used for tumor imaging in 110 patients with cancer. Scans with In-111 BLEDTA agreed with biopsy results in 75 of 95 patients (79% accuracy). A positive scan was obtained in 71 of 88 patients with a positive biopsy (81% sensitivity). In 21 of 95 patients (22%), the scan revealed tumor sites that had not been detected. The main limitation of visualization was the size of the tumor (1.5--2.0 cm diameter was the smallest size seen). Background radioactivity in the liver, spleen, and bone marrow also made tumor detection in these areas more difficult. The cause of this background, and of false-positive uptake in sites of inflammation, is correlated with specific radiolabeling of polymorphonuclear leukocytes by In-111 BLEDTA. Means of eliminating this background are discussed.

Differential interaction of antiestrogens with cytosol estrogen receptors.

Interaction of tamoxifen, trioxifene and LY117018 with cytosol-estrogen receptors from immature rat uteri was compared. Determination of relative binding affinity (RBA) by competition with [3H] estradiol under various assay conditions revealed that the RBA of LY117018 increased with temperature while that of trioxifene declined. Furthermore, the RBA values of tamoxifen and trioxifene observed after 24 h of incubation at 4 degrees C were significantly lower than those obtained with 1-h incubations. However RBA values obtained with 1- or 24-h incubations of LY117018 at 4 degrees C were similar. The complex formed by estradiol or LY117018 at 4 degrees was relatively stable for 24 h, while significant dissociation of tamoxifen and trioxifene was detected under these conditions. At 30 degrees C estradiol displayed a biphasic pattern of dissociation, but tamoxifen and trioxifene dissociated rapidly and little evidence of a stable phase was apparent. By contrast, the complex formed by LY117018 exhibited greater stability than that of estradiol at 30 degrees C. These results establish a relationship between shifts in competition curves (RBA) and rates of dissociation relative to estradiol; and clearly reveal that LY117018 has different binding characteristics than tamoxifen and trioxifene.

Kinetic analysis of LY320236: competitive inhibitor of type I and non-competitive inhibitor of type II human steroid 5alpha-reductase.

Type I and type II steroid 5alpha-reductases (5alpha-R) catalyze the conversion of testosterone (T) to dihydrotestosterone (DHT). LY320236 is a benzoquinolinone (BQ) that inhibits 5alpha-R activity in human scalp skin (Ki(typeI)=28.7+/-1.87 nM) and prostatic homogenates (Ki(typeII)=10.6+/-4.5 nM). Lineweaver-Burk, Dixon, and non-linear analysis methods were used to evaluate the kinetics of 5alpha-R inhibition by LY320236. Non-linear modeling of experimental data evaluated V(max) in the presence or absence of LY320236. Experimental data modeled to the following equation 1v=+ fixing the In0c value equal to 1.0 or 0 are consistent with non-competitive or competitive inhibition, respectively. LY320236 is a competitive inhibitor of type I 5alpha-R (In0c=0, Ki=3.39+/-0.38, RMSE = 1.300) and a non-competitive inhibitor of type II 5alpha-R (In0c=1, Ki=29. 7+/-3.4, RMSE = 0.0592). These data are in agreement with linear transformation of the data using Lineweaver-Burk and Dixon analyses. These enzyme kinetic data support the contention that the BQ LY320236 is a potent dual inhibitor with differing modes of activity against the two known human 5alpha-reductase isozymes. LY320236 represents a class of non-steroidal 5alpha-R inhibitors with potential therapeutic utility in treating a variety of androgen dependent disorders.

Characterization of type I 5 alpha-reductase activity in DU145 human prostatic adenocarcinoma cells.

The conversion of testosterone (T) to dihydrotestosterone (DHT) has been demonstrated to be catalysed by at least two isoforms of human steroid 5 alpha-reductase, designated types I and II. Type II 5 alpha-reductase expression predominates in human accessory sex tissues, localized to the fibromuscular stromal compartment. The type I isoform predominates in skin, prostatic epithelia and, to a lesser extent, in prostatic fibromuscular stroma. The significance of the type I isoform to prostatic cellular growth and function remains undefined. In cultured DU145 cells, we evaluated the metabolism of [14C]-T and demonstrated the time-dependent formation of [14C]-DHT. Oxidative metabolism (conversion of [14C]-T to [14C]-androstenedione) and the formation of conjugated androgen metabolites occurred at a relatively low rate in the DU145 cells. Using human type I 5 alpha-reductase cDNA, Northern blot analysis of DU145 cell mRNA revealed high levels of type I isoform expression. Analogous probing of the DU145 cells with a human 5 alpha-reductase II cDNA failed to reveal expression of the type II isoform. The expression of functional type I activity has been confirmed pharmacologically using isoform-selective 5 alpha-reductase inhibitors. Reductive metabolism of [3H]-T in the DU145 cells was inhibited in a concentration-dependent manner by LY306089, a potent non-steroidal type I-selective inhibitor (IC50 = 10.0 nM). SKF105657, a steroidal type II-specific inhibitor was distinctly less active at inhibiting [3H]-DHT formation. LY306089 was a non-competitive inhibitor of type I 5 alpha-reductase in DU145 cellular homogenates with an apparent Ki value of 4.0 nM. These studies have identified and pharmacologically defined type I 5 alpha-reductase activity in an androgen-insensitive prostatic cancer cell line and provide the basis for additional investigations into the significance of type I 5 alpha-reductase to human prostatic pathophysiology.

Correlation of the in vivo anticoagulant, antithrombotic, and antimetastatic efficacy of warfarin in the rat.

Fibrin formation has been hypothesized to be an element of the metastatic process in cancer, and pharmacological interference with such fibrin formation has been proposed as a means of antimetastatic therapy. We have tested this hypothesis through an in vivo study of warfarin in two independent rat disease models--a model of chemical-injury-induced arterial thrombosis, and a model of spontaneous metastasis. We found 0.50 mg/kg-day warfarin to be uniformly lethal after two weeks treatment. The chronic dose of 0.25 mg/kg-day was non-toxic and produced effective anticoagulation and marked antithrombotic and antimetastatic activity. The 0.125 mg/kg-day dose produced a reduction in factor IIc (50%) and factor VIIc (70%), and resulted in statistically significant antithrombotic and antimetastatic activity. The 0.0625 mg/kg-day dose failed to reduce the vitamin K-dependent clotting factors, and failed to produce any antithrombotic or antimetastatic effects. The substantial correlation (very similar dose-response effects) among the anticoagulant, antithrombotic and antimetastatic efficacies of warfarin in the rat suggests that anticoagulation provides the pharmacological mechanism underlying both the antithrombotic and the antimetastatic effects. The poor therapeutic index we observed in the rat may be the attribute which limits the efficacy of warfarin in the treatment of human cancer.

Prenatal in vivo bulbourethral gland development is not affected by prostaglandin E2 inhibition.

Investigation of bulbourethral gland (BUG) development is useful to study genitourinary (GU) tract growth and differentiation. Understanding GU tract growth and differentiation is relevant to testing the hypothesis that the initial lesion of human benign prostatic hyperplasia involves focal re-expression of inductive processes in the periurethral region of the prostatic transitional zone. Prostaglandins play a role in regulating growth and morphogenesis of different organ systems. Previous reports have proposed that prostaglandin E2 (PgE2) mediates the masculinizing effects of testosterone in the developing neonatal male GU tract. We have previously shown that androgens lower rather than raise BUG PgE2 levels. Further studies led us to conclude that PgE2 does not play a major role in postnatal BUG growth and morphogenesis in vitro. In order to investigate the possible role of PgE2 in prenatal BUG development, indomethacin (INDO, 1.0 mg/kg- day, subcutaneously) was administered to pregnant BALB/c mice on gestational days 12-18. Control pregnant mice were either untreated or injected with dimethylsulfoxide vehicle. Anogenital distances were measured within 12 hours after birth in male and female offspring on day 19. In male neonatal mice, BUGs were examined histologically and PgE2 levels were measured by radioimmunoassay in BUGs and whole genital tracts. We observed no significant morphological differences in INDO-exposed BUGs compared to controls. No significant differences in mean anogenital distances of INDO-exposed male offspring or controls were detected. Mean anogenital distances of female offspring were similar in the three respective groups. Mean BUG PgE2 levels in INDO-exposed neonates were significantly lower (P < 0.05) than in untreated neonates.(ABSTRACT TRUNCATED AT 250 WORDS)

Human middle-ear sound transfer function and cochlear input impedance.

The middle-ear pressure gain, defined as the ear canal sound pressure to cochlear vestibule pressure gain, GME, and the ear canal sound pressure to stapes footplate velocity transfer function, SVTF, simultaneously measured in 12 fresh human temporal bones for the 0.05 to 10 kHz frequency range are reported. The mean GME magnitude reached 23.5 dB at 1.2 kHz with a slope of approximately 6 dB/octave from 0.1 to 1.2 kHz and -6 dB/octave above 1.2 kHz. From 0.1 to 0.5 kHz, the mean GME phase angle was 51 degrees, rolling off at -78 degrees /octave above this frequency. The mean SVTF magnitude reached a maximum of 0.33 mm s(-1)/Pa at 1.0 kHz with nearly the same shape in magnitude and phase angle as the mean GME. The ratio of GME and SVTF provide the first direct measurements of Z(c) in human ears. The mean Z(c) was virtually flat with a value of 21.1 acoustic GOmega MKS between 0.1 and 5.0 kHz. Above 5 kHz, the mean Z(c) increased to a maximum value of 49.9 GOmega at 6.7 kHz. The mean Z(c) angle was near 0 degrees from 0.5 to 5.0 kHz, decreasing below 0.5 kHz and above 5 kHz with peaks and valleys.

"How I do it"--otology and neurotology. A specific issue and its solution. Advantages of the T-tube for short and long-term middle ear ventilation.

The T-tube has several advantages that should be considered when selecting a ventilation tube. First, it remains in place much longer than the average tube; thus allowing the physician, rather than chance, to determine when the tube should be removed. Second, it can be removed painlessly without an anesthetic when indicated. Third, it does not have the problem of a high post-removal perforation rate such as seen with other long term tubes. Fourth, it can be easily modified to suit the needs of the patient and the physician.

Laryngeal suspension in head and neck surgery.

Nineteen cases with major resections of the head and neck were treated with laryngeal suspension and cricopharyngeal myotomy in an attempt to allow swallowing function postoperatively and avoid a total laryngectomy. Sixteen cases were available for evaluation. Eight cases (50%) were able to eat by mouth, 15 patients (94%) had a normal airway and 14 patients (87%) had intelligible speech.

Surgery of the incompetent nasal valve.

One of the causes of nasal airway obstruction during inspiration is an incompetent nasal valve. An incompetent valve is one that collapses during quiet normal breathing due to narrowing of the valve area, a loss of upper and/or lower lateral cartilage support, or a combination of these. The most common etiology is a previous rhinoplasty; trauma and aging are other causes. Treatment is surgical and consists of replacing what is missing with similar tissue. If only the vestibular skin is scarred, a skin graft is used. If cartilage alone is missing, a cartilage graft is inserted. If both skin and cartilage are absent, a composite graft from the concha is the best choice.

Modification of the deltopectoral flap for pharyngoesophageal reconstruction.

These modifications minimize flap loss, fistulae, and stenosis, and make the final stage easier to perform. The need for periodic dilation with Maloney dilators may be required; however, we do not consider this a significant complication. The goal is a predictable result with a low complication rate so that oral feedings can begin 5 weeks after laryngopharyngectomy, and postoperative radiotherapy may be started at 6 weeks. The need for three stages may appear excessive; however, three planned stages are better than three or more unplanned stages that result in flap loss or dehiscence.

Lateral laryngeal suspension: a new procedure to minimize swallowing disorders following tongue base resection.

Fourteen patients who underwent composite resections for oropharynx and tongue base cancers had lateral laryngeal suspensions in order to improve postoperative swallowing ability, minimize the surgical defect, and decrease shifting of the mandible after composite resection. Eleven of these patients had significant base of tongue resections (30-90%) and 3 had oropharyngeal resections. Thirteen (93%) were able to eat by mouth, 14 patients (100%) had a normal airway, and 14 (100%) had intelligible speech.

Current status of topical nasal antimicrobial agents.

The nasal cavity and paranasal sinuses are probably one of the last frontiers in the head and neck region where the use of topical antimicrobial agents is not yet established. Although the anatomy of the nasal cavity and the paranasal sinuses can theoretically be exploited for the administration of antimicrobials in rhinosinusitis, very few studies have been conducted to test the feasibility of this mode of therapy. We review the anatomical and physiological factors that should be considered in the use of topical nasal antimicrobial agents and the current status of topical nasal antimicrobial usage, and we make recommendations for the administration of topical nasal antimicrobial agents.

Eye protection in the paralyzed face.

All patients with a VIIth nerve paralysis with any limitation of closure of the eye should have in the office or out-patient clinic setting: 1. paper tarsorrhaphy of the upper or possibly lower lid; 2. artificial tears and/or ointment; and 3. glasses to protect the cornea from air currents. Kinetic and static surgical procedures are discussed. The kinetic procedures include facial nerve repair and grafting, VIIth-XIIth nerve anastamosis, muscle nerve block transplantation, transposition of nonparalyzed muscle and cross over. The principals of VIIth nerve repair and grafting and presented in the intracranial, internal auditory canal, labyrinthine, tympanomastoid and extratemporal sites. The static procedures include resection of redundant skin, fascia lata strip suspension, weakening of contralateral non-paralyzed musculature, and adjunctive procedures such as resection of ptotic melolabial fold, plication of parotid-masseteric fascia, dermal graft suspension, blepharoplasty, brow lift, canthoplasty, horizontal shortening of lower lid, fascial suspension of lower lip, McLaughlin tarsorrhaphy, and palpebral spring. Patient counseling is emphasized.

The tympano-frontal shunt: a procedure for the treatment of chronic Eustachian tube insufficiency.

Eight ears with complications due to chronic eustachian tube insufficiency had insertion of a silicone rubber tympano-frontal shunt tube between the mastoid antrum and the ipsilateral frontal sinus. A one-way valve designed to open at -10 mm H20 was placed on the tympanic end of the tube to minimize tube obstruction by ear secretions. Follow-up an average of 20 months post insertion showed six of the eight ears to have an aerated middle ear without fluid or tympanic membrane retraction or perforation.