Efficacy of a new tonic containing urea, lactate, polidocanol, and glycyrrhiza inflata root extract in the treatment of a dry, itchy, and subclinically inflamed scalp

BACKGROUND/AIMS

Dry, itchy and inflamed scalp conditions are common and often associated with diseases such as atopic dermatitis or psoriasis. To improve these symptoms, we investigated the efficacy of a new tonic containing the active ingredients urea, lactate, polidocanol, and Glycyrrhiza inflata root extract, containing licochalcone A.

STUDY DESIGN/METHODS

30 subjects with dry and itchy scalp conditions underwent a randomized half-head study for 4 weeks, applying the leave-on tonic three times a week on one side of the scalp. Tonic effects on skin hydration, itching, lipids, microinflammation, and substantivity of tonic compounds were determined using corneometry, middle-infrared spectroscopy, direct analysis in real-time mass spectrometry, and enzyme-linked immunosorbent assay. Volunteers performed a self-assessment; changes in scalp condition were documented by in vivo microscopy.

RESULTS

After tonic treatment, scalp moisture was significantly increased, whereas scalp itching and tautness were significantly reduced. Results also demonstrated a high substantivity of urea and lactate on the scalp, an increase in triglyceride, and a decrease in free fatty acid levels. The amount of total lipids was unchanged. Analyses of scalp wash-ups verified a significant reduction in important pro-inflammatory markers.

CONCLUSION

Due to the actives urea, lactate, polidocanol, and the anti-inflammatory licochalcone A, the new scalp tonic exhibited excellent performance in alleviating scalp dryness, itching, microinflammation, and in normalizing disturbances of scalp lipids.

Renal transplant evaluation with MR angiography and MR imaging

Magnetic resonance (MR) angiography is a widely used, noninvasive tool for evaluating the aorta and its branches. It is particularly useful in renal transplant recipients because it provides anatomic detail of the transplant artery without nephrotoxic effects. Volume rendering is underutilized in MR angiography, but this technique affords high-quality three-dimensional MR angiograms, especially in cases of tortuous or complex vascular anatomy. An imaging protocol was developed that includes gadolinium-enhanced MR angiography of the transplant renal artery with volume rendering and multiplanar reformation postprocessing techniques. Axial T2-weighted and contrast material-enhanced T1-weighted MR images are also obtained to examine the renal parenchyma itself and to evaluate for hydronephrosis or peritransplant fluid collections. This imaging protocol allows rapid global assessment of the renal transplant arterial system, renal parenchyma, and peritransplant region. It can also help detect or exclude many of the various causes of renal transplant dysfunction (eg, stenosis or occlusion of a transplant vessel, peritransplant fluid collections, ureteral obstruction). Conventional angiography can thus be avoided in patients with normal findings and reserved for those with MR angiographic evidence of stenosis.

Vascular response to gadolinium-containing contrast media in an ex vivo rabbit arterial model

RATIONALE AND OBJECTIVES

To assess the influence of gadolinium-containing magnetic resonance contrast agents on contractility of the arterial vessel wall.

METHODS

Bilateral segments of rabbit carotid arteries were mounted in flow chambers, surrounded by aerated (95% O2, 5% CO2) Krebs' solution, and perfused at a constant rate by separated and aerated Krebs' solution. Therefore, changes in pressure of the circulating Krebs' solution indicated alterations of vessel wall contractility. Viability of the artery was tested by 124 mmol/L KCl, 3 x 10-5 mol/L phenylephrine, and 10-5 mol/L acetylcholine. After a washout phase, gadopentate (n = 10) or gadoteridol (n = 10) was added to the perfusate of one carotid artery in increments of 0.1, 0.3, and 0.6 mmol/L. Concentrations up to 0.9 mmol/L and 1.2 mmol/L were tested, respectively. The contralateral artery served as a control. To assess potential relaxing effects of the media, vessels were brought into a contracted status with 3 x 10-5 mol/L phenylephrine and then received gadolinium chelates.

RESULTS

Potassium chloride and phenylephrine increased and acetylcholine decreased the pressure, indicating vasoconstriction and vasodilatation, respectively. After gadopentate and gadoteridol infusion, no statistically significant pressure changes could be detected, ruling out any vasoconstrictor or vasodilator effect.

CONCLUSIONS

Gadopentetate and gadoteridol in doses of up to 1.2 mmol/L did not alter vessel wall tone. The impact of contrast media on blood pressure, as has been shown in some clinical trials, probably is not due to direct changes in arterial wall tone.

Percutaneous treatment of symptomatic vertebral artery stenosis with coronary stents

Atherosclerotic disease of the vertebral artery can pose a significant clinical problem. The treatment of that disease is not uniformly accepted. We report two cases of patients with vertebral basilar insufficiency due to stenosis of the vertebral artery origins and contralateral occlusions that were treated percutaneously with coronary stent placement.

Prevention of contrast medium-induced renal vasospasm by phosphodiesterase inhibition

RATIONALE AND OBJECTIVES

This study investigated the involvement of cyclic adenosine monophosphate (cAMP) in contrast medium-induced renal vasomotor effects and the efficacy of selective phosphodiesterase (PDE) inhibitors influencing cAMP in preventing contrast medium-induced renal vasospasm.

METHODS

Isometric contractions of rabbit renal artery rings were subjected to increasing concentrations of the ionic contrast medium sodium/meglumine diatrizoate (DIA) and the nonionic contrast media iopamidol (IOP) and iodixanol (IOD) and compared with a potassium chloride control. Subsequently increasing concentrations of the nonselective phosphodiesterase inhibitors theophylline and papaverine and the following selective phosphodiesterase inhibitors were applied: vinpocetine, trequinsin, zardaverine, rolipram, and dipyridamole (subtypes I-V) before restimulation of the arterial tissue with contrast medium.

RESULTS

Diatrizoate, iopamidol, and iodixanol induced contractions up to 30%, 15%, and 3.5% of the potassium chloride control, respectively. All phosphodiesterase inhibitors markedly inhibited the contrast medium-induced contractions in a dose-dependent manner. The selective phosphodiesterase inhibitors rolipram and trequinsin attenuated these contractions significantly more (92% and 94%) than did zardaverine, dipyridamole, and vinpocetine, with an inhibitory potency of 37%, 41%, and 62%, respectively.

CONCLUSIONS

Nonionic contrast media induced renal vasoconstriction less potently than ionic contrast media. Significant differences in the ability to prevent contrast medium-induced vasoconstriction were observed among the various phosphodiesterase subtypes studied. selective phosphodiesterase inhibition with inhibitor subtypes II and IV showed the most promising results in specifically preventing contrast medium-induced renal vasospasm.

Histamine release and contrast media-induced renal vasoconstriction

RATIONALE AND OBJECTIVES

The authors' purpose was to investigate the role of histamine release causing renal vasoconstriction induced by application of contrast media, an important element in contrast medium-induced nephrotoxicity.

MATERIALS AND METHODS

Isometric contractions in rabbit segmental renal arteries stimulated with KCl and increasing concentrations of the ionic contrast medium diatrizoate and the nonionic agents iomeprol and iodixanol were studied both with and without increasing concentrations of the histamine H1 and H2 blockers diphenhydramine and cimetidine. Histamine concentrations after contrast medium application were determined.

RESULTS

Contrast-induced, dose-dependent, reversible renal artery contractions of 27%, 4.5%, and 5% of the control KCl contraction were found for diatrizoate, iodixanol, and iomeprol respectively. Those induced by the ionic contrast medium were statistically significantly higher (P < .01). Contractions were partially inhibited by diphenhydramine (49%) but not by cimetidine. Significant elevation of histamine concentrations (P < .05) was detected only after stimulation with diatrizoate but not with nonionic agents.

CONCLUSION

Ionic contrast medium induces histamine release leading to renal vasoconstriction, which can be partly blocked by H1 blockers. Histamine has no effect on renal vasospasm induced by nonionic contrast media.

Role of intracellular Ca2+ stores in smooth muscle of human penile erectile tissue

OBJECTIVE

In human erectile tissue smooth muscle contraction and detumescence are highly dependent on an increase in cytosolic [Ca2+]. The Ca2+ influx can be derived from the extracellular space or from intracellular sarcoplasmic stores. The role of both pathways was evaluated in an organ bath study on human cavernosal strips.

PATIENTS AND METHODS

The tissue was obtained from 12 patients with chronic erectile dysfunction. The effects of Ca2+-free solution, ryanodine, caffeine and of nifedipine on electrically and adrenergically induced contractions were evaluated.

RESULTS

Following an incubation period of 10 min in Ca2+-free solution the electrically induced contraction was reduced to 20%, whereas the contraction induced by phenylephrine (PE) was only reduced to 64 +/- 6% (mean +/- SEM). Ryanodine inhibited the PE-contraction to 30 +/- 6% and the additional application of caffeine or nifedipine further reduced the contraction to 11% and 8%.

CONCLUSION

The results give evidence for a role of intracellular Ca2+-stores in human cavernosal tissue. Whether the more marked effect of ryanodine in tissue from patients with erectile failure in comparison with similar experiments in rabbit cavernosal tissue might be a sign of an increased cavernosal contractility in these patients remains to be shown in future experiments with normal erectile tissue.

Attenuation of contrast material-induced renal artery vasoconstriction by nitric oxide donors

RATIONALE AND OBJECTIVES

The authors studied the role of the endothelium and associated endothelial pathways in contrast material-induced renal vasoconstriction.

MATERIALS AND METHODS

Isometric contractions in human and rabbit renal artery rings with intact and denuded endothelium were stimulated with phenylephrine and increasing concentrations of the ionic contrast material diatrizoate, the nonionic contrast materials iopamidol and iomeprol, and the dimeric contrast material iodixanol in a tissue perfusion bath. Rings with intact endothelium were incubated with endothelium-stimulating compounds such as the NO synthetase inhibitor Ng nitro-L-arginine methyl ester (L-NAME) to study the endothelium-mediated vasomotor regulation and the NO-liberating substances molsidomine (SIN-1) and nitroprusside (NPR) to study the endothelial-mediated vasorelaxation before being stimulated with contrast material.

RESULTS

Contrast material-induced, dose-dependent, reversible renal artery contractions are dependent on the type of contrast material. No differences in the contractions were found between intact and denuded rings. L-NAME had no effect on contrast material-induced contractions. Contractions were inhibited by the NO donors SIN-1 and NPR. SIN-1 was the most potent inhibitor.

CONCLUSION

Contrast material-induced renal vasoconstriction is endothelium-independent. Selective pharmacologic stimulation of the endothelium by NO donors, however, may still be useful in the prophylaxis of contrast material-induced renal vasoconstriction and, thus, potentially nephrotoxicity.

Effect of contrast medium on corpus cavernosum smooth muscle

RATIONALE AND OBJECTIVES

Changes in contractility of corpus cavernosum (CC) smooth muscle caused by radio contrast medium may result in misinterpretations of cavernosography used diagnostically in erectile dysfunction.

METHODS

The authors investigated the direct effect of various contrast media on rabbit CC smooth muscle tissue strips in an in vitro model by adding contrast medium to the tissue in a perfusion bath and recording the resulting contractions. Glucose addition was used as control.

RESULTS

Application of high-osmolar, ionic contrast medium diatrizoate-induced CC smooth muscle contractions of 57% of the control potassium chloride (124 mM) induced contractions. The low-osmolar (862 mOsm/kg) nonionic monomer contrast medium, iohexol, and the iso-osmolar (300 mOsm/kg) nonionic-dimer contrast medium, iodixanol, elicited contractions of 34% and 36% of the potassium chloride control contractions, respectively. High- and Iso-osmolar glucose solutions caused contractions of 51%, 38%, and 24% of the control, respectively. Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) regulate CC smooth muscle contractions. These are influenced by different drugs including phosphodiesterases (PDEs), forskolin, and 3-morpholinsydnonimine hydrochloride (SIN-1). The nonspecific PDE inhibitors papaverine (0.1 mM) and theophylline (1 mM) reduced the contrast medium-induced contractions to 66% and 69%, respectively. The specific PDE inhibitor milrinone (0.1 mM) reduced the contractions to 69%; 0.1 mM forskolin and SIN-1 reduced the contractions to 34% and 41%, respectively.

CONCLUSIONS

Contrast medium induces CC smooth muscle contractions, depending mainly on the osmolality of the solution. The contractions are reduced but not abolished by elevating the intracellular cAMP and cGMP concentrations. The clinical applications in cavernosography are discussed.

Comparison of iodinated contrast media-induced renal vasoconstriction in human, rabbit, dog, and pig arteries

RATIONALE AND OBJECTIVES

Contrast media (CM)-induced renal vasoconstriction is an important factor in the pathogenesis of CM-induced nephrotoxicity. The effects of ionic, high-osmolar CM sodium/meglumine diatrizoate and nonionic, low-osmolar CM iohexol and iopamidol were studied in rabbit, dog, and pig renal arteries and compared with human tissue in an organ bath.

METHODS

Isometric contractions were induced by increasing concentrations of CM and high-osmolar glucose solution.

RESULTS

Contrast media and glucose elicited contractions in human renal arteries of 32% (diatrizoate), 20% (iohexol), 30% (iopamidol), and 22% (glucose). Rabbit and dog renal arteries demonstrated contractions of 30% and 46% (diatrizoate), 15% and 23% (iohexol), 15% and 26% (iopamidol), and 11% and 40% (glucose), respectively, of the control. There was a vasorelaxing effect of all CM tested on pig renal artery.

CONCLUSIONS

Responses in rabbit and dog renal arteries were similar to those in human renal arteries and could serve as models for investigating CM-induced renal vasoconstriction.

Comparative regulation of alpha1-adrenergic receptor mediated contraction in urogenitally derived smooth muscle. Effect of epidermal growth factor

Contractility of smooth muscle within mammalian urogenital organ systems has an established role in physiological/pathophysiological functioning of the component structures. Our aim was to examine the direct effect of epidermal growth factor (EGF) on smooth muscle tone as well as its indirect effects in regulating alpha1-adrenoceptor-mediated contraction of the prostate, the vas deferens and renal arteries. Tissues were mounted isometrically, under controlled conditions, and changes in tension in response to treatment with phenylephrine (PE) with or without pretreatment with EGF were recorded on a physiological recorder via force transducers. In the rabbit prostate, EGF potentiated the magnitude of contraction to PE. The potentiation appeared to be dependent on cyclo-oxygenase products. In the human prostate, EGF potentiated the contractile response to PE. EGF had no effect on the PE-induced contraction of the rabbit renal artery and vas deferens. EGF alone did not alter smooth muscle tone in any of the above-mentioned tissues. The main finding of this study is the difference in the regulation by EGF of the alpha1-adrenoceptor-mediated response in smooth muscle of the prostate, from that by the vas deferens and renal artery. The reasons for this difference in response remain to be elucidated. This study may form the basis for further investigation into receptor transregulation and its relevance to symptomatic benign prostatic hyperplasia (BPH).

Variable effects of iodinated contrast media on different rabbit arteries in vitro

Vasoconstriction caused by iodinated contrast media (CM) has been considered specific for the renal artery only. We examined the vascular effect of CM in rabbit carotid, aorta, renal, iliac, mesenteric and celiac arteries and found that other arteries also respond with a contraction to CM. Isolated arterial rings were exposed to diatrizoate (high osmolar CM), iohexol (low osmolar CM) or glucose solution, and the isometric contraction response was expressed as percentage of an initial KCl control contraction. Diatrizoate evoked contractions of 82% (carotid), 63% (aorta), 30% (renal), 24% (iliac), 28% (mesenteric) and 18% (celiac), respectively. Iohexol caused contractions of 31% (carotid), 24% (aorta), 15% (renal) and 14% (iliac), whereas the mesenteric and celiac arteries were relaxed by iohexol. A high osmolar glucose solution elicited contractions of 78%, 77%, 11%, 27%, 3% and 5%, respectively, in the arteries. CM have contraction potency in arterial vasculature other than the renal artery.

Role of intracellular calcium stores in contrast medium-induced renal vasoconstriction

RATIONALE AND OBJECTIVES

Renovascular smooth muscle contractility, an important factor in contrast media-induced nephrotoxicity, depends on intracellular Ca2+ concentration, which is composed of extracellular Ca2+ influx and intracellular Ca2+ release. These factors were investigated in contrast media-induced renal vasoconstriction in an in vitro model.

METHODS

KCl-induced isometric contractions of rabbit renal artery were compared with contractions elicited by contrast media (diatrizoate, iohexol, iopamidol). Measurements were made after incubation with the Ca2+ channel blockers nifedipine, verapamil, and diltiazem to assess the role of extracellular Ca2+ influx and after ryanodine and thapsigargin to investigate the role of intracellular Ca2+ release.

RESULTS

The Ca2+ channel blockers partially inhibited contractions induced by contrast media, while KCl-induced contractions were completely abolished. Ryanodine and thapsigargin also markedly inhibited contrast media-induced contractions.

CONCLUSION

Ionic and nonionic contrast media induced quantitatively different renal vasocontractions. Ca2+ channel blockers inhibited this vasocontraction only slightly compared with intracellular Ca2+ release blockers.

The dominant phosphoprotein pp65 (UL83) of human cytomegalovirus is dispensable for growth in cell culture

The phosphoprotein pp65 (ppUL83) of human cytomegalovirus (HCMV) is abundantly synthesized during lytic infection in cultured fibroblasts. As a major constituent of extracellular particles, it gains entry to infected cells immediately after adsorption and subsequently translocates to the cell nucleus. This efficient transport is mediated by unique nuclear localization signals. To study the function of pp65, a viral deletion mutant was constructed by replacing the pp65 gene with the bacterial neomycin phosphotransferase gene, driven by the simian virus 40 early promoter. The resulting virus, RVAd65, could be grown and selected on human fibroblasts without complementation. The deletion of the pp65 gene in RVAd65 was verified by using Southern blot and PCR analyses. The lack of expression from the gene was investigated by immunoblotting with pp65-specific monoclonal antibodies. Single-cycle growth analyses showed that RVAd65 grew to levels of infectivity comparable to those of the wild-type virus. Therefore, pp65 is nonessential for the growth of HCMV in human fibroblasts. Electron microscopy revealed no differences in the processes of virion morphogenesis, although the maturation appeared to be delayed. However, the kinetics of expression of the immediate-early genes UL122 and UL123, the early gene UL44, and the late gene UL32 were the same in RVAd65-infected cells as in wild-type virus-infected cells in immunoblot analyses. In vitro phosphorylation assays showed that some of the virion proteins were labelled to a markedly reduced extent by virion-associated kinases in RVAd65 compared with wild-type virus. We therefore conclude that although deletion of the pp65 gene does not abolish replication of HCMV, a recombinant virus lacking pp65 displays phenotypic alterations compared with wild-type virus during growth in cultured fibroblasts.

Ca2+ and cyclic adenosine monophosphate involvement in radiographic contrast medium-induced renal vasoconstriction

PURPOSE

To investigate the role of extracellular Ca2+ and cyclic 3'-5' adenosine monophosphate (cAMP), a known second messenger promoting smooth muscle relaxation, in preventing renal vasoconstriction induced by radiographic contrast medium (RCM).

MATERIALS AND METHODS

Isometric contractions of rabbit renal artery were elicited by potassium chloride and increasing concentrations of meglumine/sodium diatrizoate. To determine the contribution of extracellular Ca2+, nifedipine, a blocker of voltage-dependent L-type Ca2+ channels (VDCC), was applied. The contribution of cAMP was investigated by applying the nonspecific phosphodiesterase (PDE) inhibitors papaverine and theophylline and the specific PDE inhibitor milrinone, all of which prevent degradation of cAMP. Forskolin, an activator of cAMP by stimulating adenylyl cyclase (AC), was also investigated.

RESULTS

RCM elicited contractions that were 24.5% of the KCl control contraction, which was reduced by nifedipine (100 mumol/L) by 34.7%. Papaverine, theophylline, and milrinone inhibited RCM-induced contractions by 69.8%, 64.3%, and 43.7%, respectively. Forskolin reduced the response by 82.2%.

CONCLUSION

Ca2+ influx through VDCC partially contributes to RCM-induced renal artery vasoconstriction. Intracellular cAMP appears to be an important second messenger pathway for prevention of this response. These findings emphasize the role of second messenger systems involved in adverse RCM effects and the potential prevention of these effects.

Nuclear targeting of the tegument protein pp65 (UL83) of human cytomegalovirus: an unusual bipartite nuclear localization signal functions with other portions of the protein to mediate its efficient nuclear transport

Large amounts of pp65 (UL83) of human cytomegalovirus are translocated to the cell nucleus during the first minutes after uptake of the tegument protein from infecting viral particles. Two stretches of basic amino acids which resembled nuclear localization signals (NLS) of both the simian virus 40 type and the bipartite type were found in the primary structure of pp65. Deletion of these sequences significantly impaired nuclear localization of the truncated proteins after transient expression. The results indicated that both elements contributed to the nuclear localization of the protein. When fused to the bacterial beta-galactosidase, only one of the two basic elements was sufficient to mediate nuclear translocation. This element consisted of two clusters of basic amino acids (boxes C and D), which were separated by a short spacer sequence. In contrast to other bipartite NLS of animal cells, both basic boxes C and D functioned independently in nuclear transport, thus resembling simian virus 40-type NLS. Yet, complete translocation of beta-galactosidase was only found in the bipartite configuration. When both boxes C and D were fused, thereby deleting the intervening sequences, the nuclear transport of beta-galactosidase was reduced to levels seen with constructs in which only one of the boxes was present. Appropriate spacing, therefore, was important but not absolutely required. This was in contrast with results for other bipartite NLS, in which spacer deletions led to complete cytoplasmic retention. The presented results demonstrate that efficient nuclear transport of pp65 is mediated by one dominant NLS and additional targeting sequences. The major NLS of pp65 is an unusual signal sequence composed of two weak NLS which function together as one strong bipartite nuclear targeting signal.

Regulation of prostatic smooth muscle contractility by intracellular second messengers: implications for the conservative treatment of benign prostatic hyperplasia

The increased sympathetic neurotransmission in benign prostatic hyperplasia (BPH) results in a alpha 1C-adrenoceptor-mediated increase in prostatic smooth muscle tone which seems to be responsible for the dynamic infravesical obstruction occurring in BPH. The prostatic smooth muscle contractions evoked by norepinephrine can be efficiently blocked by alpha 1-adrenoceptor blockers. Moreover, an impressive number of clinical trials illustrated the beneficial results of alpha 1-adrenoceptor blockers in the treatment of BPH. However, despite knowledge of alpha 1-adrenergic neurotransmission and the clinical application of its blockade by selective alpha 1-adrenoceptor antagonists, very little is known about the intracellular pathways involved in the regulation of prostatic smooth muscle contractility. To study the intracellular mechanism of the alpha 1C-adrenoceptor-induced prostatic smooth muscle contraction, the patch-clamp technique in the whole-cell configuration mode combined with the Fura-II fluorescence technique was used in human, enzymatically isolated smooth muscle cells obtained from patients undergoing transurethral resection of the prostate because of symptomatic BPH. Furthermore changes in prostatic smooth muscle contractility were registered in organ bath experiments. Application of the selective alpha 1-adrenoceptor agonist phenylephrine (PE) increased the L-type Ca(2+)-channel current (ICa) dose dependently from 8 up to 18.5 microA/cm2, simultaneously elevating the free cytoplasmic Ca2+ concentration ([Ca2+]i) up to 1.9 microM. Pretreating the myocytes with pertussis toxin, an exotoxin of Bordetella pertussis which inactivates GTP-binding proteins (G proteins) of the Gi and G(o) family by ADP ribosylation, reduced the PE-induced ICa stimulation by 71.5 +/- 5.6% (n = 21). Dialysis of the cytosol with the second messenger inositol-1,4,5-trisphosphate (IP3), which releases Ca2+ from intracellular non-mitochondrial, IP3-sensitive Ca2+ pools, imitated the PE-evoked responses. Pretreating the myocytes with the Ca(2+)-release blockers ryanodine (10-100 microM, n = 8), thapsigargin (0.1 microM, n = 11) or low-molecular weight heparin (n = 14) largely attenuated the PE-evoked responses. The experimental results suggest a coupling of alpha 1-adrenoceptors to phospholipase C-converting phosphoinositol-4,5-bisphosphate into diacylglycerol, an endogenous activator of the protein kinase C and IP3 which releases Ca2+ from intracellular stores stimulating ICa via Ca(2+)-calmodulin-dependent protein kinase induced phosphorylation of voltage-dependent Ca2+ channels. This knowledge could be of interest for conservative treatment in symptomatic BPH.

Ryanodine-sensitive intracellular Ca2+ stores in isolated rabbit penile erectile tissue

Norepinephrine release from adrenergic nerve terminals leads to a rise in intracellular Ca2+, which promotes penile smooth muscle contraction and detumescence. Ca2+ sources are the extracellular space and sarcoplasmic Ca2+ stores. To elucidate the role of intracellular stores strips from rabbit erectile tissue were investigated in an organ bath study. Contractions were elicited by phenylephrine (PE) and electrical stimulation. Incubation in Ca(2+)-free solution as well as exposure to nifedipine did not abolish electrical or PE-induced contraction. Ryanodine (10(-5) mol/l), a functional blocker of sarcoplasmic Ca2+ channels, significantly reduced PE response. In the presence of caffeine (10(-3) mol/l) the effect was significantly enhanced. Addition of nifedipine nearly abolished the contraction. These results provide evidence for intracellular Ca2+ pools in cavernosal tissue and indicate that the alpha 1-adrenoceptor-induced contraction requires the opening of voltage-gated Ca2+ channels and the release of Ca2+ from intracellular stores.

Smooth muscle tone regulation in rabbit cavernosal and spongiosal tissue by cyclic AMP- and cyclic GMP-dependent mechanisms

The relaxing effects of several specific and nonspecific inhibitors of phosphodiesterases (PDE) on rabbit isolated corpus cavernosum (CC) and spongiosum (CS) were investigated. Preparations were mounted in organ baths, and isometric tension was recorded. The results were compared with the effects of direct administration of analogs of the second messenger cyclic nucleotides and the effects of forskolin, a direct stimulator of adenylate cyclase, and the nitric oxide donor 3-morpholinosydnonimine (SIN 1). All drugs relaxed the phenylephrine-induced contractions in CC and CS in a dose-dependent fashion. In CC and CS, type III (SK&F 95654) and type V (zaprinast and dipyramidole) PDE inhibitors, as well as the nonspecific inhibitors papaverine and trequinsin, showed no differences in IC50. The type IV inhibitor rolipram relaxed CC and CS at significantly lower concentrations (p < 0.005) than any other PDE inhibitor, and in CC the type III and IV inhibitor zardaverine was more potent (p < 0.05) than SK&F 95654. SIN 1 stimulates guanylate cyclase and effectively inhibits contractions in CC and CS. Activation of adenylate cyclase by forskolin also was highly effective (p < 0.005). It is concluded that PDE inhibition constitutes an effective relaxing mechanism in rabbit CC and CS. The marked effects of the different types of PDE inhibitors support the importance of cyclic guanosine 3',5'-monophosphate and cyclic adenosine 3',5'-monophosphate in smooth muscle relaxation in erectile tissue.

Reduced levels of IE2 gene expression and shutdown of early and late viral genes during latent infection of the glioblastoma cell line U138-MG with selectable recombinants of human cytomegalovirus

To establish stable culture conditions which support persistence of the human cytomegalovirus (HCMV) genome in a latent state, the expression of the bacterial neomycin phosphotransferase (neo) from HCMV recombinants was used for selection. Different cell lines were infected with HCMV recombinants. The human glioblastoma line U138-MG was rendered resistant to G418 and retained the viral genome. More than 90% of the cells expressed the viral IE1 protein of 72 kDa for a culture period of 18 months. Many fewer cells expressed IE2-encoded proteins. No late gene expression or infectious virus was detectable. IE2 gene expression in latently infected cells appeared to be restricted at the level of RNA accumulation. Treatment with TPA or retinoic acid led to enhanced expression of the IE2 gene and the early genes encoding pp65 (UL83) and p52 (UL44). Superinfection with wild-type HCMV led to replication of neo-recombinant virus, indicating that replication-competent virus had been retained in latently infected U138-MG and that the cells had kept their permissive phenotype. Latent HCMV infection in U138-MG cells provides a useful model system for studying the role of particular viral and cellular genes in latent and permissive infections.

Isolation and biological activity of aspidospermine and quebrachamine from an Aspidosperma tree source

The indolealkaloids aspidospermine and quebrachamine have been isolated in crystalline form by a relatively rapid fractionation from the extract of a powdered material designated "Quebracho" derived from an Aspidosperma tree species. We present a novel isocratic LC method that provides baseline resolution of these two compounds and of the structurally related yohimbine in less than 15 min. Gas chromatography-mass spectrometry was employed to identify these compounds as well as several minor derivatives of aspidospermine during and after the purification process. Aspidospermine and quebrachamine like yohimbine have been found to possess adrenergic blocking activities for a variety of urogenital tissues.

Smooth muscle contractility in prostatic hyperplasia: role of cyclic adenosine monophosphate

The role of cyclic 3'-5' adenosine monophosphate (cAMP) on alpha 1-adrenoceptor (alpha 1-receptor) induced smooth muscle contractions in symptomatic benign prostatic hyperplasia (BPH) was investigated. Application of the selective alpha 1-receptor agonist phenylephrine (PE) induced fully reversible contractions in a dose-dependent fashion. Phosphodiesterase (PDE) inhibitors blocking the degradation of cAMP suppressed the PE induced contractions as follows: theophylline (1 mM), 91.1 +/- 1.4%; papaverine (0.5 mM), 822.8 +/- 3.2%; milrinone (0.5 mM), 68.2 +/- 0.6%. Forskolin (50 microM), which elevates cAMP through direct activation of adenylatecyclase (AC), inhibited the PE induced contractions by 82.4 +/- 3.6%. To further increase the intracellular cAMP concentration ([cAMP]i), the membrane permeable cAMP analogue N6-2'-O-dibutyryladenosine derivative (dBcAMP; 1 mM) was applied and reduced the PE evoked contractions by 69.8 +/- 2.3%. We conclude that elevation of [cAMP]i is an important step in inducing smooth muscle relaxation.

G-proteins in alpha 1-adrenoceptor mediated prostatic smooth muscle contraction

The role of signal transducing guanine-nucleotide binding proteins (G-proteins) in alpha 1-receptor mediated smooth muscle contractions was investigated in human hyperplastic prostatic tissue. The selective alpha 1-receptor agonist phenylephrine (PE) evoked dose dependent contractions antagonized by the alpha 1-receptor blockers prazosin (EC50 10 nM) and YM617 (EC50 3 nM). Application of nifedipine (1-10,000 nM), a blocker of voltage-dependent L-type Ca(2+)-channels (VDCC), inhibited the PE evoked contraction up to 65.4%. Pretreating the tissue strips with pertussis toxin (PTX, exotoxin from Bordetella pertussis; 5-25 micrograms/ml), inactivating a subpopulation of G-proteins, inhibited the PE induced contractions up to 73.9%. PTX pretreatment had no effect on contractions elicited by 125 mM K+. Application of nifedipine to PTX pretreated tissue led to an additional inhibition of 13.7%. Our findings demonstrate the involvement of PTX-sensitive G-proteins in the signal transduction pathway of alpha 1-receptor induced contractions of prostatic smooth muscle. The remaining contractility of PTX pretreated tissue suggests additional participation of PTX insensitive mechanisms in alpha 1-receptor mediated prostatic smooth muscle contractions.

Role of intracellular Ca2+ stores in smooth muscle contractions of the guinea pig vas deferens

Guinea pig vas deferens was used as an animal model for alpha-1 adrenoceptor (alpha 1-receptor) mediated contractions in human hyperplastic prostatic tissue. The selective alpha 1-receptor agonist, phenylephrine (PE), induced fully reversible, dose-dependent contractions antagonized by increasing concentrations of the alpha 1-receptor blockers prazosin (1-100 nM) and YM 617 (0.1-10 nM). Removal of extracellular Ca2+ reduced PE-evoked contractions in a time-dependent manner. Nifedipine (1-1000 nM), a blocker of voltage-dependent L-type Ca2+ channels (VDCC), inhibited the PE-induced response by up to 65%. Removal of extracellular Ca2+ abolished the alpha 1-agonist reactivity in a time-dependent fashion. To elucidate the participation of intracellular Ca2+ stores in alpha 1-receptor-mediated contractions, the tissue was pretreated with ryanodine (10 microM) or thapsigargin (0.1 microM), established inhibitors of Ca2+ release from intracellular pools. Both substances reduced the PE contractions by up to 80%. Nifedipine suppressed the remaining contractions completely. This provides evidence that Ca2+ influx through VDCC and Ca2+ release from intracellular stores contribute to alpha 1-receptor-mediated contractions in the guinea pig vas deferens and may be important in obstructive benign prostatic hyperplasia.

[New imaging methods in thoracic diagnosis. A study to evaluate digital storage screen radiography, the slit technique ("AMBER"), asymmetric ("InSight") and conventional film-screen techniques]

New methods have been introduced in recent years in chest imaging to achieve high image quality simultaneously in the mediastinum and in the lung field. In this study the clinical value is assessed for four techniques: digital storage phosphor radiography, slit-technique ("AMBER"), asymmetrical film/screen ("InSight") and conventional film/screen. 43 patients were examined with these techniques within one day. Seven readers of four universities graded the image quality according to ten criteria of the mediastinum and the lung field. The slit-technique ("AMBER") showed the best image quality in both areas. Compared to conventional film/screen, storage phosphor radiography and asymmetrical film/screen ("InSight") yield better image quality only in the mediastinum.

[Detection of a pheochromocytoma in the urinary bladder wall]

We present the case of a 23-year old female patient with clinical signs and biochemical results of a pheochromocytoma. Abdominal ultrasound gave no hints on localisation. Angiography demonstrated a richly vasculated tumour in the region of the superior urinary bladder. Computed tomography (CT) was able to localise the tumour but could not differentiate the tumour origin in bladder or uterus. The selective venous catheter blood sampling confirmed the localisation of the norepinephrine producing pheochromocytoma in the inferior pelvic region. Intraoperative diagnosis turned out to be an extra-adrenal pheochromocytoma of unknown tumour status in the dorsal bladder wall.

[Current developments in the radiologic diagnosis of the adrenal glands]

Cross-sectional imaging techniques have dramatically improved the diagnosis of adrenal disease. In most patients with endocrine-active adrenal disease, CT is the only imaging test needed to establish the correct diagnosis. Adrenal venography with blood sampling may provide important additional information in patients with Conn adenoma. Magnetic resonance imaging and (IMBG) scintigraphy appear to be the best imaging tests for the localization of multiple or extra-adrenal pheochromocytomas. Inactive adrenal tumors detected incidentally are a problem as for as diagnosis is concerned, since inactive adrenal adenomas have to be differentiated from carcinomas and metastases. MRI is rarely helpful in these cases. For patients with a known primary tumor, the authors recommend CT-guided biopsy. In all other cases a follow-up study often reveals that the adrenal tumor detected is benign.