Correlation of ultrasonographic and orchidometer measurements of testis volume in adults.

OBJECTIVE: To determine the correlation between testicular volume measured with an orchidometer or high-resolution scrotal ultrasonography (US) with colour-flow Doppler analysis. PATIENTS AND METHODS: In all, 159 men (mean age 36.6 years) presenting for infertility evaluation underwent both a physical examination by a one experienced examiner and high-resolution US with colour-flow Doppler analysis. An orchidometer was also used to measure testicular volume after stretching the scrotal skin tightly over the testis and after warming with a heating pad. The US was interpreted by a radiologist who had no knowledge of the orchidometer estimates. The volume was calculated as 0.71 x length x width x height. RESULTS: For the right testes the mean orchidometer and US estimates were 18.4 and 18.3 mL, yielding a correlation coefficient of 0.72 (r (2) = 0.52, P < 0.01). On the left the respective values were 17.1 and 16.9 mL, with a correlation coefficient of 0.69 (r (2) = 0.48, P < 0.01). CONCLUSION: Orchidometer estimates of testicular volume correlate closely and very significantly with US estimates in adults. In the hands of an experienced examiner orchidometer measurements provide an accurate, rapid and inexpensive assessment of testicular volume.

Androgens induce the expression of vascular endothelial growth factor in human fetal prostatic fibroblasts.

Androgens are known to directly stimulate prostate cancer cell growth. We have previously reported that LNCaP prostate cancer cells were dependent upon stromal coinoculation for growth in nude mice and that the stromal cells secreted a potent angiogenic factor, vascular endothelial growth factor (VEGF), which stimulated tumor angiogenesis. Immunohistochemical staining localized VEGF expression primarily to the stromal cells of human fetal and adult hyperplastic prostates, with both stromal and epithelial cell VEGF expression in prostate cancer. In the present studies, we test the hypothesis that androgens, in addition to their direct effects on prostate epithelial cells, have indirect effects on these cells via up-regulation of stromal VEGF production and angiogenesis. Primary cultures of human prostate fetal fibroblasts were treated with dihydrotestosterone (DHT), and the effects on VEGF messenger RNA (mRNA) expression were determined by Northern blotting. DHT (10 nM) increased VEGF mRNA levels maximally after 2 h. Nuclear run-on transcription assays demonstrated a 2-fold increase in the VEGF transcription rate 2 h after the addition of DHT. VEGF mRNA stability was unaffected by DHT addition. VEGF protein levels were determined by enzyme-linked immunosorbent assay and were increased 2-fold 4 h after DHT addition. These data indicate that androgens increase VEGF transcription and secretion of biologically active VEGF from human prostatic stroma. Androgens, therefore, may indirectly enhance prostate growth via up-regulation of VEGF from the surrounding stroma.

Inhibition of vascular endothelial cell growth factor suppresses the in vivo growth of human prostate tumors.

The LNCaP human prostate cancer cell line is androgenand stromal-dependent for in vivo growth. We co-inoculated LNCaP cells with human fetal fibroblasts, isolated from prostate, bone (male), and lung (male and female) derived from 18- to 22-week-old human fetal tissue, into non-castrate male nude mice. Co-inoculation of LNCaP with fetal prostatic fibroblasts resulted in high tumor take rates (27 of 30, or 90%) 6 to 8 weeks after subcutaneous co-inoculation. Serum prostate specific antigen (PSA) values correlated strongly with wet tumor weight (r=0.86). The fetal fibroblast enhancement of tumor take rates in vivo was neither gender- nor organ-specific. Fetal fibroblast-conditioned medium (CM) did not have a significant proliferative effect on LNCaP cell growth in vitro. Areas of angiogenesis were demonstrable in all tumors, with blood vessels arising at the interface between stromal and tumor cells. The fetal fibroblasts, but not the LNCaP cells, expressed significant amounts of the mRNA and protein for vascular endothelial cell growth factor (VEGF). Treatment of tumor-bearing animals with neutralizing antibodies to VEGF resulted in significant tumor growth suppression. These findings indicate that VEGF is an important mediator of stromal-induced enhancement of human prostate cancer cell growth in vivo.

A simple program in BASIC for least-squares fitting of certain equations to experimental data.

A program is presented that fits certain classes of theoretical equations to experimental data by the method of least squares. Equations that can be fitted by this program include all one-parameter functions and those two-parameter functions in which one of the parameters is a multiplicative factor. The program is in BASIC and thus can be used on any microcomputer equipped with that language, and its use is guided by on-screen prompts.

Least squares fit of data to hyperbolic dose-response curves using a programmed minicalculator (TI-59).

Equations of the Michaelis-Menten form are frequently encountered in a number of areas of biochemical and pharmacological research. A program is presented for use on the programmable TI-59 calculator with added printer which performs an iterative least-squares fit of up to 80 data pairs to this equation and estimates the standard deviations and standard errors of the determined parameters. The program assigns equal weights to errors over the entire data range and is thus appropriate for situations in which data precision is independent of amplitude.

Effects of increasing osmolality on rat ileal smooth muscle.

The effects of changing bathing medium osmolality on tension generation in smooth muscle were studied on potassium-depolarized segments of rat ileum. Increasing the tonicity of the medium evokes a transient relaxation of the smooth muscle; restoration of isotonicity evokes a transient contraction of similar amplitude and time course. While immersed in hypertonic media of less than 1.3 times normal tonicity, the smooth muscle slowly increases its isometric tension; in media of nearly twice normal tonicity, the smooth muscle loses tension. All of these effects occur whether the medium is made hypertonic with added NaCl or sucrose.

Two mechanisms of isoproterenol inhibition of smooth muscle.

The relaxation of depolarized ideal and uterine smooth muscle by isoproterenol was compared with that brought about by dibutyryl-cAMP and by other agents which increase cytoplasmic cAMP. Qualitative differences observed between the time courses of the relaxations imply the existence of a rapid beta-adrenergic mechanism independent of cAMP as well as a slower cAMP-dependent relaxation. This dual process model for beta-adrenergic inhibition of smooth muscle is consistent with seemingly opposing published reports.

Role of the sympathetic innervation of the pacinian corpuscle.

An investigation was made into the nature of the role played by the noradrenergic innervation of the pacinian corpuscle. Corpuscles of the cat mesentery and mesocolon were used in all experiments. Blockade of noradrenergic beta receptors by dichloroisoproterenol and interference with norepinephrine release by reserpine are each capable of reversibly blocking mechanoelectric transduction by the pacinian corpuscle. The monoamine oxidase inhibitors iproniazid and phenelzine are capable of protecting the transducer from the blocking effects of reserpine. It is concluded that the presence of norepinephrine, as maintained by sympathetic tonus, is required for the afferent nerve terminal of the pacinian corpuscle to be mechanosensitive.