The effects of chronic high dose androgen or estrogen treatment on the human prostate [corrected

Prostate development and disease are androgen dependent. However, the nature of hormonal effects on the prostate of healthy young men is not clear. We, therefore, measured prostate size in males chronically exposed to high doses of androgens (AS; habitual anabolic steroid abusers; n = 15) or estrogens (E; male to female transsexuals; n = 11) and compared the results with those in age-matched healthy eugonadal men without known prostate disorders. Prostate size was measured by planimetric ultrasound as cross-sectional areas and maximal dimensions in three orthogonal dimensions with a 7.5-megahertz B-mode sector scanner biplane in a transrectal transducer at 2.5 mm steps from the base to the apex of prostate. Total prostate volume (TPV) was reconstructed from planimetric sections, central prostate volume (CPV) was calculated by the ellipsoidal formula from the appropriate three maximum dimensions, and peripheral prostate volume was determined by the difference between TPV and CPV. Compared with age-matched controls, TPV was normal (-2%) in AS (P = 0.752) and reduced by 31% in E (P = 0.002), whereas CPV was increased by 20% in AS (P = 0.002) and reduced by 46% in E (P = 0.002), and the ratio of CPV/peripheral prostate volume was increased by 77% in AS (P < 0.001) and decreased by 33% in E (P = 0.047). Blood sex hormone-binding globulin was elevated by nearly 500% in E (P < 0.001), but was reduced by 47% in AS (P = 0.003). Prostate-specific antigen was normal (-6%) in AS (P = 0.799) and decreased by 86% in E (P = 0.002). Prostatic acid phosphatase was increased by 26% in AS (P = 0.007), but was unchanged (-28%) in E (P = 0.106). Total and free testosterone levels were reduced to castrate levels in E, whereas LH, FSH, and total testosterone levels were significantly reduced in AS. We conclude that in the human prostate of young men, CPV is more hormonally sensitive than TPV, and during high dose treatment, CPV is preferentially increased by chronic androgen treatment and decreased by chronic estrogen treatment. The reduction of TPV by estrogens was less than expected if solely attributable to inhibition of endogenous gonadotropin and testosterone secretion, suggesting that estrogens also have a positive effect on the normal human prostate. The reversibility and long term significance of androgen-induced stimulation of CPV and, in particular, its relationship to the onset and severity of benign prostatic hyperplasia remain to be clarified.     

Amifostine (WR-2721) shortens the engraftment period of 4-hydroperoxycyclophosphamide-purged bone marrow in breast cancer patients receiving high-dose chemotherapy with autologous bone marrow support

4-Hydroperoxycyclophosphamide (4-HC), a commonly used marrow-purging agent, is active against many tumors, but is also toxic to normal marrow progenitors. Amifostine (WR-2721) is a sulfhydryl compound with chemoprotectant activity. Preclinical studies using suspensions of bone marrow and breast cancer cells demonstrated that ex vivo treatment with amifostine followed by 4-HC resulted in protection of marrow progenitors, with no compromise in the antitumor effect of 4-HC. This fact stimulated the development of a clinical trial. Bone marrow was harvested from 15 poor-prognosis breast cancer patients and randomly assigned to ex vivo treatment with amifostine followed by 4-HC (amifostine + 4-HC), or treatment with 4-HC alone. High-dose chemotherapy was then administered followed by infusion of the purged autologous bone marrow support (ABMS). Leukocyte engraftment, defined as a white blood cell count > or = 1 x 10(9)/L, was achieved in an average of 26 days for patients whose marrow was purged with amifostine + 4-HC versus 36 days for patients whose marrow was purged with 4-HC alone (P = .032). The average number of platelet transfusions (12 v 29; P = .017) and days of antibiotic therapy (28 v 40; P = .012) were significantly less for patients whose marrow was exposed to amifostine + 4-HC, compared with 4-HC alone. Unpurged backup marrow fractions were infused into three patients whose marrow was purged with 4-HC alone, because of inadequate marrow recovery. None of the patients who received amifostine + 4-HC-purged marrow required a backup marrow fraction. Complete remissions were achieved in 83% of patients with measurable disease, with no difference between the two cohorts. Forty-three percent of patients remained alive and progression-free at a mean of 13 months posttransplant. There was no significant difference in the rate or pattern of relapse for patients whose marrow was purged with amifostine + 4-HC compared with those whose marrow was purged with 4-HC alone. Ex vivo treatment of marrow with amifostine significantly shortens the time to marrow recovery, thereby reducing the risk of myelosuppressive complications in breast cancer patients receiving high-dose chemotherapy and 4-HC-purged ABMS. Since supportive care requirements are also significantly decreased, amifostine may reduce the cost of such therapy.     

FTIR characterization of heterocycles lumazine and violapterin in solution: effects of solvent on anionic forms

Fourier transform infrared (FTIR) spectra have been obtained from solution samples of the heterocycles uracil, lumazine, and violapterin and reveal interpretable carbonyl stretching frequencies. Spectra of conjugate bases of lumazine and violapterin demonstrate decreases in these carbonyl stretching frequencies upon ionization. Based on isotopic shifts from amide deuterated analogs, semiempirical QCFF/PI calculations were used to assign the vibrational frequencies in the region 1100-1800 cm-1 observed from samples in dimethylsulfoxide (DMSO) and aqueous solutions to specific normal modes. The observed deuterium shifts and the calculations suggest that, in some cases, N-H bending motions are coupled to the C=O stretching motions of the pyrimidine ring. These data suggest that for lumazine anions a change in solvent can significantly change the mixing of the N-H bending and C=O stretching vibrational motions. This implies that vibrational analysis for lumazine species in relatively noninteracting media like nonpolar solvents, mulls or pellets cannot necessarily be transferred to the system when it is dissolved in a polar, hydrogen-bonding solvent such as water. Although other explanations can be offered, our vibrational analysis suggests that the changes in normal mode composition of the predominantly C=O stretching vibrations of lumazine anion on going from dimethylsulfoxide to water solution are consistent with a change in the predominant tautomer of the heterocycle. This change appears to correspond to a shifting of the location of the remaining acidic proton to a different ring nitrogen atom. This interpretation is of interest in view of recent ab initio calculations which suggest that proton shifts may occur during the hydroxylation of lumazine as mediated by the enzyme xanthine oxidase.     

Acetylation of core histones causes the unfolding of 30 nm chromatin fiber: analysis by agarose gel electrophoresis

In the present work it was directly demonstrated that increased acetylation level of histones causes the decompactization of 30 nm chromatin fiber, as revealed by low-percentage agarose gel electrophoresis. In the light of obtained results the possible molecular mechanism of the decompactization of acetylated fiber is discussed.     

Superior activity of a thromboxane receptor antagonist as compared with aspirin in rat models of arterial and venous thrombosis

We determined the effects of aspirin and a novel thromboxane A2/prostaglandin endoperoxide (TP)-receptor antagonist, BMS-180291, on thrombosis and bleeding times in skin and mesenteric arteries. In anesthetized rats, occlusive thrombosis was induced in the carotid artery by topical application of ferrous chloride and in the vena cava by blood flow stasis combined with either infusion of thromboplastin or hypotonic saline. Aspirin (1, 10, and 50 mg/kg) did not reduce arterial or venous thrombus weight significantly. BMS 180,291 (150 micrograms/kg/min) decreased arterial thrombus weight and hypotonic saline-induced caval thrombus weight by 58 and 57%, respectively. BMS-180291 lacked antithrombotic activity at a lower dose (50 micrograms/kg/min) and failed to inhibit thromboplastin-induced caval thrombosis. BMS-180291 (150 micrograms/kg/min) significantly reduced arterial thrombus weight by 40% when plasma epinephrine concentration was increased to 5 ng/ml. BMS-180291 and aspirin produced increases of only < or = 30% in bleeding times. These results demonstrate that BMS-180291 has antithrombotic activity in experimental aspirin-resistant arterial and venous thrombosis. Both aspirin and BMS-180291 have only modest effects on small artery hemostasis in rats.     

Clinical evaluation of technetium-99m-L,L-ethylenedicysteine in patients with chronic renal failure

1. Effects of feeding condition from birth were examined on the sensitivity of neuromuscular transmission to d-tubocurarine (dTc) in vitro in male mice of the ddY strain. 2. Mice were trained to climb two separated cylindrical steel-wire tubes for feeding and drinking, respectively, from 16 days of age. Some mice were conventionally fed, from 99 days of age. Nerve-muscle preparations were made from the left phrenic nerve diaphragm muscle (DPH), the sciatic nerve soleus muscle (SOL), and the sciatic nerve extensor digitorum longus muscle (EDL) of 99-day-old and 155-day-old mice. The nerve trunk was electrically activated with trains of four pulses and tetanic pulses. 3. The sensitivity to the effects of dTc decreased in the order EDL, SOL, and DPH. This result held true in all mice tested. 4. This sensitivity was significantly potentiated by the compulsory movement. 5. The supersensitivity remained even when mice were conventionally fed after 99 days of age. 6. The compulsion rendered EDL antifatigable on tetanic stimulation. This property was also retained after a return to conventional feeding. 7. These results suggest that the effects of feeding condition from birth might remain on neuromuscular functions after termination of the conditioning.     

Kinetics of intermetallic compound growth between nickel,electroless, Ni-P,electroless Ni-B and tin at 453 to 493 K

The growth kinetics, crystal structure, and morphology of the intermetallic compounds formed between nickel, electroless Ni-P and electroless Ni-B coatings with tin at 453 to 493 K for times up to 506 h have been determined by microscopical and X-ray diffraction techniques. The compound Ni₃Sn₄ was formed. All kinetics followed as parabolic law with activation energies of 128.0, 130.4, and 122.3 kJ mol^–1 for the Ni/Sn, Ni-P/Sn and Ni-B/Sn systems, respectively. The rate of growth of Ni₃Sn₄ in the Ni/Sn and Ni-P/Sn systems were similar but the rate of growth in the Ni-B/Sn system was five times faster. Pores occurred in the intermetallic compound formed in the Ni-P/Sn system and these are discussed in relation to the density of the phases.