[Treatment mapping of lower urinary tract symptoms due to benign prostatic hyperplasia-an analysis of the Governing Body of German Prostate Centers]. / Versorgungsabbild des benignen Prostatasyndroms ­ eine Analyse des Dachverbandes der Prostatazentren Deutschlands (DVPZ) e. V.

BACKGROUND: Due to the high incidence and demographic development, there is an urgent need for healthcare research data on lower urinary tract symptoms due to benign prostatic hyperplasia (LTUS/BPH). Since 2005 the Governing Body of German Prostate Centers (DVPZ) has been collecting data from 22 prostate centers in order to determine the quality and type of cross-sectoral care in particular for LUTS/BPH patients. OBJECTIVES: Presentation of the DVPZ database in general, as well as an investigation of treatment patterns for medical and instrumental therapies. MATERIALS AND METHODS: The analysis is based on UroCloud data sets from 30 November 2017. In the UroCloud data on diagnostics, therapy and course of disease are recorded in a web-based manner. RESULTS: A total of 29,555 therapies were documented for 18,299 patients (1.6/patient), divided into 48.5% instrumental, 29.2% medical treatment, and 18.0% "wait and see" (in 4.3% no assignment was possible). Patients treated with an instrumental therapy were oldest (median: 72 years, interquartile range: 66-77), had the largest prostate volumes (50 ml, 35-75 ml), and were mostly bothered by symptoms (International Prostate Symptom Score = 19/4). The majority of patients under medical treatment received alphablockers (56%); phytotherapeutics were used least frequently (3%). Instrumental therapies are dominated by transurethral resection (TUR) of the prostate (60.0%), open prostatectomy (9.4%) and laser therapy (5.0%), with laser therapy having the shortest hospital stay (5 days) and the lowest transfusion and re-intervention rates (1.0% and 4.6%, respectively). CONCLUSIONS: The DVPZ certificate covers the complete spectrum of cross-sectoral care for LUTS/BPH patients and documents the use of the various therapies as well as their application and effectiveness in the daily routine setting.

Occupational exposure to ultrafine particles in police officers: no evidence for adverse respiratory effects.

BACKGROUND: Inhalation exposure to fine and ultrafine particles (UFPs) has been associated with respiratory diseases. However, little is known on the quality, threshold levels and concentration of these particles causing adverse health effects. METHODS: The impact of occupational exposure to submicrometer and UFPs was assessed in 30 healthy police shooting instructors by clinical investigation, self-assessment questionnaire, sputum and spirometry and compared to a control group. General laboratory chemistry parameters, circulating cytokines (interleukin [IL]-2, IL-4, IL-5, IL-6, IL-8, interferon-gamma [IFN-γ]), and granulocyte macrophage colony-stimulating factor (GM-CSF) in serum were measured. UFP exposure was recorded by Scanning Mobility Particle Sizer. RESULTS: Concentrations of submicrometer sized airborne particles (< 700 nm) measured between 3.34 × 105/cm3 and 7.58 × 105/cm3 at shooting sites, with highest concentrations found in the UFP range (< 100 nm). The size of the monodispersed particles ranged from 54.74 ± 16.25 nm to 98.19 ± 22.83 nm. Short term exposure (4 h) to high levels of UFPs caused an increase of IFN-γ in exposed subjects (p = 0.022). 24 h after exposure a significant decrease of IgG, albumin fibrinogen and factor VII was found. Neither directly after 4 h of high levels UFPs exposure nor 24 h after exposure subjective complaints or objective measurements indicating adverse respiratory effects in exposed subjects were found. CONCLUSIONS: No consistent indications for adverse respiratory or inflammatory effects directly following exposure and 24 h after exposure to high levels of UFPs in our study group were detected. However we showed the assessment of short-term exposure effects at a genuine occupational setting, which might is relevant when a risk assessment of high level occupational exposures to UFPs is considered.

[Treatment mapping of prostate cancer in DVPZ prostate centers in Germany]. / Versorgungsabbild zum Prostatakarzinom in DVPZ-Prostatazentren in Deutschland.

BACKGROUND: In prostate centers of the Governing Body of German Prostate Centers (DVPZ, Dachverband der Prostatazentren Deutschlands e.V.) treatment data from 3 university clinics, 21 treatment clinics, 3 private clinics and 330 general practitioners incorporated under 22 certificates are collated, in order to document the quality and type of cross-sectoral and interdisciplinary treatment, in particular of prostate cancer (PCA) patients. METHODS: This analysis is based on the DVPZ UroCloud data sets from 20 July 2015. The UroCloud reflects the web-based chronological disease development and quality parameters. For the descriptive analysis of particular key figures, available complete data sets were selected. RESULTS: Of the centers 22 held a valid certificate and fulfilled all required case numbers and structural prerequisites at the primary certification or recertification. In three cases a reauditing led to requirements before certification. Since 2005 a total of 9650 PCA patients have been pseudonymized and followed up (41,247 follow-up forms, 4.3 forms per patient). In 2014 the median number of newly documented PCA patients was 61 per center (minimum 7 and maximum 295). Radical prostatectomy (RP) dominated with 4491 (56 %) cases followed by primary hormonal therapy (1210 cases, 15 %), irradiation (809, 10 %) and non-interventional therapy, such as active surveillance (AS) or watchful waiting (WW) in 760 cases (10 %). A prostate-specific antigen (PSA) reduction was documented in 50 % of the patients with a preoperative PSA value > 20, in 60 % of pT4 tumors and in 50 % of patients with a tumor Gleason score of 9-10. A positive incision margin (R+) was found in in 15 % of pT2 stages, 41 % of pT3 stages and 85 % of pT4 stages. A secondary intervention was documented in 6.5 % of RP. CONCLUSION: The DVPZ certificate reflects the complete spectrum of treatment of PCA patients. The strength of the certificate lies in the documentation of patient development and a simultaneous collation of quality parameters.

The infiltration of the AC joint performed by one specialist: ultrasound versus palpation a prospective randomized pilot study.

INTRODUCTION: The acromio-clavicular (AC) joint is very susceptible to degenerative processes that result in pain and functional impairment. One common modality of treatment has been local infiltration of the joint space. Although this procedure has produced notable positive results, needle misplacement occurs frequently. The aim of this investigation is to evaluate the effects of an intra articular infiltration by comparing precise needle placement into the joint space using high-resolution-ultrasound with the conventional palpation technique. METHODS: This prospective and randomized pilot study analysed 20 patients who were assigned either to the "ultrasound" or the "palpation" group. Clinical examinations were performed before treatment and at 1h, 1 week and 3 weeks after a single infiltration of local anaesthetic and corticoid carried out by one specialist. RESULTS: In both groups significant improvement in pain and function was obtained up to one-week post injection. Function remained significantly improved until the last follow-up and did not differ between the two groups. The agent was administered in all patients into the joint space in the ultrasound group. CONCLUSION: Ultrasound guided infiltration of the AC joint is an easily achieved procedure without any complications. However, clinical follow-up did not differ between free-hand and ultrasound-guided AC joint space infiltration.

Accidents and injuries in competitive Enduro motorcyclists: a prospective analysis.

The Erzberg Rodeo Motor Enduro race, was analyzed over three consecutive years to analyze the risk of sustaining an accident, to determine the kind and site of injured body regions and to correlate the incidence of accidents with the site on the race track suspiring that most accidents happen at the first- and the last-third. In this prospective, field study questionnaires were used recoding fallen riders. Demographic data, the third of the race track on which the accident happened and details of the accident itself like its mechanism were noted. Each injured body region was recorded separately and rated according to the abbreviated injury scale. Two thousand nine hundred and twenty-three athletes started in 3 years in the Erzberg Rodeo; 6% of them had an accident and 94% were non-professionals. Overall, the average abbreviated injury scale was 2.8. More than 80% of all counted injuries were superficial. Most accidents happened in a curve due to the front tire sliding, affecting mostly arm and leg. Overall 67% of all accidents happened at day 1 of the race and 41% of all accidents happened in the first-third of the race track. Competitive Enduro motorcyclists have a high risk of sustaining an accident, but in comparison a low risk of sustaining a severe injury. Curves are the predominant site of accidents.

The Enduro motorcyclist's wrist and other overuse injuries in competitive Enduro motorcyclists: a prospective study.

According to public opinion, Enduro motorcycling is a dangerous sport. Little is known about overuse injuries in connection with this sport. The study consisted of two phases. Phase 1 was planned as a prospective feasibility study for phase 2. The latter was initiated as a prospective investigation, comprising a random sample of the participants of phase 1. Enduro motorcyclists were interviewed with a prepared questionnaire. Clinical examinations were performed immediately before, and after, a major Enduro race, including pain assessment in the hand/wrist and the forearm using the visual analog scale. The occurrence of Raynaud's syndrome carpal tunnel syndrome (CTS), and loss of grip strength in the forearm muscles were recorded in detail. Phase 1 showed that the predominant overused anatomical regions were the hand/wrist and forearms. Nearly 50% of all the riders complained of pain or paresthetic sensations. A significant increase in pain was registered after the race. After the second run 32.28% of all riders had CTS in the left hand and 43.31% in the right hand. More than one-half of the athletes complained of overuse injuries. Transient CTS is an overuse injury closely related to sports.

[Prevention of heterotopic ossification after THA with indomethacin: analysis of risk factors]. / Ossifikationsprophylaxe nach Hüft-TEP mit Indomethacin: Analyse von Risikofaktoren.

AIM: Several risk factors are associated with heterotopic bone formation following total hip replacement. All these risk factors were defined in cohorts without any treatment against postoperative ectopic bone. The aim of this prospective study was to reveal risk factors for the development of postoperative ossifications in patients who underwent a 7-day course of indomethacin therapy. METHODS: 211 consecutive patients with 217 cementless total hip arthroplasties were included. Patients were given 100 mg indomethacin daily in a 7-day course. RESULTS: Grade 2 or 3 ossifications were observed in 13 (5%) of the male and 3 (2%) of the female Individuals postoperatively (p = 0.0043; odds ratio = 0.45). Older individuals (p = 0.0021; odds ratio = 1.03) as well as patients with primary osteoarthritis (p = 0.0307; odds ratio = 0.28) also showed a higher risk for developing ectopic bone formations. CONCLUSION: With a 7-day course of indomethacin after total hip arthroplasty, male and elderly individuals, as well as patients with primary osteoarthritis, are considered to be at high risk to develop heterotopic ossifications postoperatively. Indomethacin reduces the incidence of postoperative ectopic ossifications, but not the patient's risk.

Optical coherence tomography guided retreatment of photodynamic therapy.

AIM: To evaluate the results of a retreatment modality of photodynamic therapy (PDT) based on optical coherence tomography (OCT) and fluorescein angiography (FA). To quantify the effect of PDT with the help of measurement of the retinal thickness. METHODS: Eyes with predominantly classic subfoveal choroidal neovascularisation (CNV) due to age related macular degeneration were included. PDT was performed every three months, when needed. OCT, FA, and measures of distance acuity were performed at baseline, after 6 weeks, 3 months, and from then on every 3 months. A control group of a consecutive series of eyes that had been retreated based only on FA results was installed. RESULTS: Forty eyes of 38 patients were included. The average age was 73 years. The maximum retinal thickness decreased from 404 mum at baseline to 281.6 mum at month 12. Furthermore there was a significant decrease of retinal thickness in both subgroups. The number of retreatments was reduced, when activity was diagnosed using OCT and FA. (2.4 v 4.0). The distance acuity correlated significantly with the maximum retinal thickness (p=0.0042). CONCLUSION: Information about the activity of a neovascular lesion can be obtained with the help of OCT. The retreatment modalities can be optimised by using OCT and FA and the number of retreatments can be reduced.

Fetal and juvenile animal hemorheology.

The study provides information on the blood fluidity in healthy, juvenile sheep and rabbits during growth (n = 18), and shows also data from fetal rabbits and cats. In the fetal rabbit (n = 3) and cat (n = 2), whole blood viscosity (WBV; LS30, Contraves, Switzerland) and plasma viscosity (PV; OCR-D, Paar, Austria) was low (WBV (0.7 s(-1)): rabbit: 3.28/3.00/2.44; cat: 7.87/10.88; WBV (94 s(-1)): rabbit: 2.57/2.48/2.39; cat: 2.75/3.73 mPa s) (PV: rabbit: 1.10/1.10/1.05; cat: 1.27/1.39 mPa s), which was associated with a low plasma protein concentration and a low erythrocyte count despite a high erythrocyte volume. After parturition, blood viscosity increased in rabbits in parallel with hematocrit, while MCV decreased (WBV (0.7 s(-1)): 9.28 (8.07/10.88); WBV (94 s(-1)): 3.67 (3.62/3.82); PV: 1.15 (1.15/1.25) mPa s). In contrast, in the sheep, whole blood and plasma viscosity decreased after delivery (WBV (0.7 s(-1)): 1.31 (0.94/1.88); WBV (94 s(-1)): 2.45 (2.43/2.85) PV: 1.24 (1.23/1.29) mPa s). Hematocrit and MCV decreased, while erythrocyte count increased under these circumstances. In summary, whole blood viscosity was similar among fetal sheep, rabbits, and cats and is diminished compared to adult individuals to guarantee an optimal oxygen supply during a period of life in which the oxygen maintainance of the child depends on the health and the environment of the mother. However, during growth, blood viscosity rose in rabbits, while it continuously decreased in the sheep. At an unknown time point this fall in blood viscosity in lambs must reverse, since adult sheep again show a higher blood viscosity than juvenile lambs at the age of 2 months.

Clinical course and histopathologic risk factor assessment in patients with bilateral testicular germ cell tumors.

OBJECTIVES: To determine whether the clinical course or the histopathologic risk factor assessment of the secondary tumor justifies early detection of the premalignant testis, since only 5% of contralateral testicular biopsies in the case of a testicular tumor reveal a testicular intraepithelial neoplasia (TIN). METHODS: From 1975 to 1997, 30 patients with bilateral germ cell tumors were treated; histologic and clinical data were available in all patients. In 12 patients, histopathologic re-evaluation and immunohistochemical staining of both tumors was performed for risk factor analysis. RESULTS: At the time the primary tumor was diagnosed, the mean patient age was 28 years. The metachronous secondary tumors were detected after a mean of 5.6 years. Seminoma was the predominant histologic finding in primary (53%) and secondary (56%) tumors. Eighty-three percent of patients had clinical Stage I (Lugano classification) disease at the diagnosis of the secondary tumor and 17% Stage II. Only 3 of 12 secondary tumors showed vascular invasion. The proliferation analysis (MIB-I score) showed a mean proliferation rate of only 34% within the primary and 26% within the secondary tumors. CONCLUSIONS: The results of our study show that the low clinical stage and good outcome associated with a histologic low-risk score of the secondary tumor does not mandate contralateral biopsy to detect TIN at the time of diagnosis of the first tumor.

Hepatitis C virus infection risk factors in patients admitted in hospital emergency departments in Picardy. Value of oriented screening based on recommendations of the 'Direction Générale de la Santé'.

OBJECTIVE AND DESIGN: Oriented hepatitis C virus (HCV) screening on the basis of transfusion, previous or current parenteral drug addiction, invasive procedures, and in family members of patients with hepatitis C, was recommended in France by the 'Direction Générale de la Santé' (DGS). The aim of this study was to estimate the frequency of these risk factors in patients admitted in hospital emergency departments in Picardy. METHODS: Between 1 June and 31 July 1996, physicians of the emergency units of seven hospitals in Picardy were asked to question admitted patients about risk factors mentioned in the DGS recommendations, and to suggest a screening test when at least one of these risk factors was present. RESULTS: Among 1648 patients, 68.7% had at least one of these risk factors. Screening was accepted by 723 patients, 58.7% of those with at least one risk factor, and more than 70% of those with history of transfusion and/or drug addiction. It was immediately performed in 451, and 2.4% had anti-HCV antibodies. The prevalence of anti-HCV antibodies was 1.5% in patients without history of transfusion or drug addiction and 7.9% in those with at least one of these two risk factors. CONCLUSION: Oriented screening based on transfusion or drug addiction history seems to have better efficiency than the screening policy recommended by the DGS. Poor reliability of answers about medical history was observed probably because of stress related to emergency circumstances. A screening test proposed to patients with these major risk factors by their usual physician would be probably more efficient.

[Testicular loss due to hemorrhagic infarct in Tauber antegrade scrotal varicocele sclerotherapy]. / Hodenverlust durch hämorrhagische Infarzierung bei antegrader skrotaler Varikozelensklerosierung nach Tauber.

A 38-year-old patient with a grade 3 testicular varicocele was treated by antegrade scrotal sclerotherapy. Although performed technically accurate, antegrade sclerotherapy led to a haemorrhagic infarction of the testis by complete occlusion of venous drainage. The testis had to be removed. This complication has not been described yet and patients should be informed about this rare event.

Safety and tolerability of zalcitabine (ddC) in patients with AIDS or advanced AIDS-related complex in the European expanded access programme.

This international expanded access programme was initiated to provide zalcitabine (o 75 mg three times daily) to patients with AIDS or advanced ARC who had failed, were no longer able to tolerate or were ineligible to receive zidovudine (ZDV). Data are available from 517 patients. No unexpected adverse events occurred during the study with 13.2% of patients discontinuing treatment due to drug-related adverse events. Peripheral neuropathy (PN) was the most common adverse event reported. This was considered to be at least possibly related to zalcitabine in 12.2% of patients, with only 2.3% of patients withdrawing from the study due to zalcitabine-associated PN. Patients with a baseline diagnosis of AIDS and a CD4 count

Comprehensive allelotyping of human renal cell carcinomas using microsatellite DNA probes.

The von Hippel-Lindau locus on chromosome 3p is a tumor suppressor gene known to be involved in nonpapillary renal cell carcinoma. A previous loss of heterozygosity (LOH) study aimed at determining the allelotype of kidney tumors has indicated that in addition to 3p, chromosome arms 5q, 6q, 10q, 11q, 17p, and 19p may also harbor tumor suppressor genes. However, cytogenetic studies reveal that chromosomes 3p, 6q, 8p, 9pq, and 14q most frequently undergo karyotypic changes in renal tumors. To resolve these differences, a collection of microsatellite DNA probes has been used to scan for LOH so that 90% of individual tumor genomes were rendered informative for allele loss. The assay is capable of detecting quantitative genomic alterations in tumor cells as well. We find that LOH is most frequent for chromosome arm 3p. However, in no tumor is 3p exclusively affected. LOH for 6q, 8p, 9pq, and 14q is also distinctly elevated for both nonpapillary as well as papillary tumors and suggest that many of the tumor suppressor loci involved may be common to the etiology of both forms of kidney cancer.

[Pancreatic-portal fistula and subcutaneous fat necrosis]. / Fistule pancréatico-portale et cytostéatonécrose sous-cutanée.

The pancreaticoportal fistula is a very uncommon complication of pancreatic diseases, mostly occurring in the course of chronic pancreatitis. From 2 findings of pancreaticoportal fistula and a literature review, we emphasize in this study the frequency of subcutaneous fat necrosis during pancreaticoportal fistula, the pathogenic role of the pancreaticoportal fistula to induce a subcutaneous fat necrosis by means of a massive enzyme release in the systemic circulation, the protective role of portal thrombosis, and finally the diagnostic and therapeutic value of endoscopic retrograde cholangio-pancreatography in pancreaticoportal fistula.

Characteristics of the binding of the antihypertensive agent moxonidine to alpha 2-adrenoceptors in rat brain membranes.

The characteristics of the alpha 2-adrenoceptor binding property of moxonidine (4-chloro-N-(4,5-dihydro-1H-imidazol-2-yl)-6-methoxy-2-methyl-5-pyrim idinamine, BDF 5895), a newly developed centrally acting antihypertensive agent, was investigated in receptor binding assays using [3H]-rauwolscine bound to rat cortex membranes. The results are as follows: 1. [3H]-Rauwolscine binds in a saturable manner to rat cerebral cortex membranes with a Bmax of 320 +/- 50 fmol/mg of protein and KD of 1.7 +/- 0.5 nmol/l. 2. The alpha 2-adrenoceptor antagonist yohimbine competes with a Ki value of 8.0 nmol/l and slope factor close to unity. (--)-Norepinephrine competes with an overall Ki-value of 50 nmol/l and slope factor of 0.61. Mg2+ concentrations of 10 mmol/l in the presence of 0.1 mmol/l 3'-guanylimidodiphosphate (Gpp(NH)p) (Mg2+/Gpp(NH)p) do not affect the yohimbine inhibition curve, but increase the (--)-norepinephrine Ki value to 2.8 mumol and the slope factor to unity. 3. Moxonidine competes with [3H]-rauwolscine binding with an overall Ki value of 460 nmol/l and slope factor of 0.72. Moxonidine binding inhibition was potentiated by Mg2+, but shifted to lower potency by Mg2+/Gpp(NH)p and 150 mmol/l NaCl. 4. Binding inhibition curves for (--)-norepinephrine and moxonidine fitted better to a 2-site model and could be interpreted in terms of high affinity site (with Ki value KH) and low affinity site (with Ki value KL). The effect of Mg2+/Gpp(NH)p and NaCl was to convert the high affinity sites to low affinity sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction between calcium channel ligands and calcium channels.

Distinct drug receptors for 1,4-dihydropyridines, phenylalkylamines, and the benzothiazepine d-cis-diltiazem exist on voltage-dependent calcium channels. The drug receptors show reciprocal allosteric communication and are linked to calcium binding sites. The 1,4-dihydropyridine-selective receptor (probed with [3H]nimodipine) has a size (measured by radiation inactivation) identical in heart, skeletal muscle, and brain (180 kDa). To compare the sizes of 1,4-dihydropyridine receptors in different tissues, pure tritiated enantiomers of the arylazido photoaffinity probe [3H]azidopine were used to irreversibly label the purified 1,4-dihydropyridine receptor (155, 65, and 32 kDa) from guinea pig skeletal muscle transverse tubules and the membrane-bound cardiac receptor. The 155 kDa polypeptide region, but not the 65 or 32 kDa bands, was specifically labelled by (-)-[3H]azidopine. (+)-[3H]Azidopine did not label any of the polypeptides in the purified receptor preparation. In contrast with the results from other investigators, a 155 kDa polypeptide was also specifically labelled in cardiac membranes by (-)-[3H]azidopine. A 34 kDa photolabelled band carries a low-affinity 1,4-dihydropyridine binding site that has no obvious relation to the channel but is abundant in heart membranes and has apparently led to erroneous results in previous affinity or photoaffinity labelling experiments. Antibodies raised against the purified skeletal muscle channel precipitate the 125I-labelled 155 kDa channel polypeptide from skeletal muscle and precipitate the three drug receptor sites from both crude and purified channel preparations. We conclude that all three drug receptor sites are localized on this polypeptide.

Photoaffinity labelling of the cardiac calcium channel. (-)-[3H]azidopine labels a 165 kDa polypeptide, and evidence against a [3H]-1,4-dihydropyridine-isothiocyanate being a calcium-channel-specific affinity ligand.

The arylazide 1,4-dihydropyridine (-)-[3H]azidopine binds to a saturable population of sites in guinea-pig heart membranes with a dissociation constant (KD) of 30 +/- 7 pM and a density (Bmax.) of 670 +/- 97 fmol/mg of protein. This high-affinity binding site is assumed to reside on voltage-operated calcium channels because reversible binding is blocked stereoselectively by 1,4-dihydropyridine channel blockers and by the enantiomers of Bay K 8644. A low-affinity (KD 25 +/- 7 nM) high-capacity (Bmax. 21.6 +/- 9 pmol/mg of protein) site does not bind (-)- or (+)-Bay K 8644, but is blocked by high concentrations (greater than 500 nM) of dihydro-2,6-dimethyl-4-(2-isothiocyanatophenyl)-3,5-pyridinedicarboxy lic acid dimethyl ester (1,4-DHP-isothiocyanate) or, e.g., (+/-)-nicardipine. (-)-[3H]Azidopine was photoincorporated covalently into bands of 165 +/- 8, 39 +/- 2 and 35 +/- 3 kDa, as determined by SDS/polyacrylamide-gel electrophoresis. Labelling of the 165 kDa band is protected stereoselectively by 1,4-dihydropyridine enantiomers at low (nM) concentrations and by (-)- and (+)-Bay K 8644, whereas the lower-Mr bands are not. Thus, only the 165 kDa band is the calcium-channel-linked 1,4-dihydropyridine receptor. Photolabelling of the 39 or 35 kDa bands was only blocked by 10 microM-1,4-DHP-isothiocyanate or 50 microM-(+/-)-nicardipine but not by 10 microM-(-)-Bay K 8644. [3H]-1,4-DHP-isothiocyanate binds to guinea-pig heart membranes with a KD of 0.35 nM and dissociates with a k-1 of 0.2 min-1 at 30 degrees C. [3H]-1,4 DHP-isothiocyanate irreversibly labels bands of 39 and 35 kDa which are protected by greater than 10 microM-(+/-)-nicardipine or unlabelled ligand but not by 10 microM-(-)-Bay K 8644. Thus, [3H]-1,4-DHP-isothiocyanate is not an affinity probe for the calcium channel.

Stereoselective photoaffinity labelling of the purified 1,4-dihydropyridine receptor of the voltage-dependent calcium channel.

The voltage-dependent calcium channel from guinea-pig skeletal muscle T-tubules has been isolated with a rapid, two-step purification procedure. Reversible postlabelling of the channel-linked 1,4-dihydropyridine receptor and stereoselective photolabelling as a novel approach were employed to assess purity. A 135-fold purification to a specific activity of 1311 +/- 194 pmol/mg protein (determined by reversible equilibrium binding with (+)-[3H]PN200-110) was achieved. Three polypeptides of 155 kDa, 65 kDa and 32 kDa were identified in the purified preparation. The 155-kDa band is a glycoprotein. The arylazide photoaffinity probe (-)-[3H]azidopine bound with high affinity to solubilized membranes (Kd = 0.7 +/- 0.2 nM) and highly purified fractions (Kd = 3.1 +/- 2 nM), whereas the optical antipode (+)-azidopine was of much lower affinity. Irradiation of (-)-[3H]azidopine and (+)-[3H]azidopine receptor complexes with ultraviolet light led to preferential incorporation of the (-) enantiomer into the 155-kDa polypeptide in crude solubilized and purified preparations. The pharmacological profile of irreversible labelling of the 155-kDa glycoprotein by (-)-[3H]azidopine is identical to that found in reversible binding experiments. Specific photolabelling of the 155-kDa band by (-)-[3H]azidopine per milligram of protein increases 150-fold upon purification, whereas incorporation into non-specific bands in the crude solubilized material is identical for both, (-) and (+)-[3H]azidopine.