A study of androgen-resistant subjects indicates that the 6.7 pI/56 kDa protein in genital skin fibroblasts is related to the androgen receptor

Two-dimensional gel electrophoresis of cultured human skin fibroblast lysates reveals a silver-stained "spot" of molecular mass 56 kilodaltons (kDa) and isoelectric point (pI) 6.7, occasionally as part of a doublet with a minor pI 6.5 partner. Its presence in each of 23 genital skin fibroblast strains (6 labium majus, 17 prepuce) and its absence in 30 of 32 control non-genital skin fibroblast strains accords with the 3-fold greater concentration of androgen-receptor activity in the former. However, the size and intensity of the spot do not change when cells are preincubated for 48 hours with 3 nM methyltrienolone (MT, a non-metabolizable androgen), and it is pulse-labeled with [35S]methionine to an autoradiographically equal extent, with or without incubation in 3 nM MT for 2 or 16 hours. Furthermore, the protein identified by the spot is found in the labium majus skin fibroblast strains from 2 of 12 unrelated subjects with complete androgen resistance due to negligible androgen-receptor activity, but it is absent from those of 2 others who have the same phenotype despite a normal level of qualitatively abnormal androgen-receptor activity. Hence, it is very unlikely to be an androgen-induced protein, and it cannot be a functional version of the androgen receptor itself. Its absence in 12 of 14 labium majus strains of subjects with complete androgen resistance, regardless of 5 alpha-reductase activities, indicates that it is neither a constitutive cytotypic marker of genital skin fibroblast differentiation nor a reflection of that enzyme. When intact prepuce fibroblasts are covalently labeled by photolysis with 50 nM [3H]MT, the only specific labeling detectable after two-dimensional electrophoresis is in the 6.7 and 6.5 pI doublet of the 56 kDa protein. Considering the sensitivity of silver staining and the incomplete concordance between the androgen-receptor activity of a strain and the size/intensity of its 6.7 pI/56 kDa spot on the gels, we postulate the latter to be a comparatively abundant androgen-binding protein that is causally related to the androgen receptor. The precise nature of this relation remains to be elucidated by use of novel immunologic and/or nucleic acid probes for this protein and for the mature androgen receptor. In any event, the presence or absence of the 6.7 pI/56 kDa protein in genital skin fibroblast lysates is a new marker of genetic heterogeneity within the class of complete androgen resistance.

Effects of isosorbide dinitrate and diltiazem on Ca2+ flux and contraction in artery

We studied the effects of isosorbide dinitrate and diltiazem on histamine-stimulated 45Ca fluxes and contractions of isolated porcine coronary artery. Isosorbide dinitrate was slightly more potent as an inhibitor of intracellular compared to extracellular calcium-dependent contraction. Isosorbide dinitrate inhibited histamine-stimulated calcium efflux and intracellular calcium-dependent contraction over similar concentration ranges. Isosorbide dinitrate partially inhibited histamine-stimulated calcium influx, but this effect was significant only at high concentration and correlated weakly with inhibition of contraction that was dependent on extracellular calcium. Diltiazem more potently inhibited extracellular vs. intracellular calcium-dependent contraction. Diltiazem partially inhibited histamine-stimulated calcium efflux and intracellular calcium-dependent contraction to similar extents (55-60%) and produced similar concentration-response relationships for inhibition of histamine-stimulated calcium influx and extracellular calcium-dependent contraction. The data suggest that alterations of cellular calcium metabolism are major mechanisms of vascular smooth muscle relaxation by isosorbide dinitrate and diltiazem, but that the specific alterations differ for the two drugs. Isosorbide dinitrate may inhibit contraction primarily by enhancing intracellular calcium sequestration, but possibly also by inhibiting agonist-stimulated calcium influx at high isosorbide dinitrate concentrations. Diltiazem primarily inhibits stimulated calcium influx, but may also inhibit intracellular calcium release.

Evaluation of surgical staples for ligation of the renal pedicle during nephrectomy

A mechanical stapling instrument was evaluated for ligation of the renal pedicle during nephrectomy in nine healthy sheep. Two forms of disposable loading unit, from which stainless steel surgical staples could be dispensed in double or triple staggered row configuration, were assessed for their proper function when applied across the renal pedicle singularly or in series. The response of the sheep to surgery was assessed by physical, hematological, and serum chemistry evaluations. Tissue healing was determined by gross and histopathological examinations. Ligation and transection of the pedicle took 2 to 4 minutes. The vessels of the pedicle ranged in diameter from 3 to 12 mm. In two sheep, overzealous stripping of perivascular tissue from the renal pedicle prior to placement of a triple staggered row of staples resulted in mild hemorrhage from the renal stump. This was controlled by placing a second triple staggered row of staples proximal to the first. It was concluded that ligation of the renal pedicle could be performed rapidly, effectively, and safely in healthy sheep using the correctly applied mechanical stapler. It is inferred that a similar technique would be applicable to other species including man.

Vasodilatory action of amlodipine on rat aorta, pig coronary artery, human coronary artery, and on isolated Langendorff rat heart preparations

Amlodipine inhibited contractions of rat aortic rings induced by 40 mM KCl (IC50 = 7.5 x 10(-9) M). The time to attain the maximum inhibitory effect of KCl-induced contractions was long (hours) and dependent on the concentration of amlodipine. After 6 h of washing in drug-free normal Krebs-Ringer solution the contractions recovered only partially. The KCl-induced contractions appeared to be more sensitive to inhibition by amlodipine than were norepinephrine-induced contractions. CaCl2-induced contraction of KCl-depolarized aortic rings was inhibited by amlodipine in a complex manner. Amlodipine not only increased ED50 but also inhibited the maximal tension induced by CaCl2. Amlodipine also inhibited 35 mM KCl-induced contractions of pig coronary artery rings (IC50 = 2.2 x 10(-8) M) and human coronary artery rings (IC50 = 2.1 x 10(-8) M). In Langendorff rat heart preparations, low concentrations of amlodipine increased coronary flow (ED50, 10(-9) M) whereas higher concentrations (greater than 10(-7) M) decreased coronary flow. Amlodipine also decreased the rate of contraction (+ dP/dt, IC50 = 3 x 10(-7) M) and the rate of relaxation (-dP/dt, IC50 = 1.2 x 10(-7) M). Amlodipine decreased heart rate but only at high concentrations (greater than 300 nM). The results of this study indicate that amlodipine is a potent vasodilator with similar cardiovascular actions to other dihydropyridines except that its effects are slower in onset and longer lasting.

[Lipid myopathy: a heterogenic familial case]

A case is reported of lipid storage myopathy in a 24-year-old patient and her family. In the patient and an aunt, muscle biopsy disclosed intrafibrillar lipid depositions, and electron microscopy revealed lipid vesicles in the sarcolemma border. In the father, no lipid depositions were observed but electron microscopy showed alterations to mitochondria compatible with a mitochondrial myopathy. In the patient muscular biochemistry revealed a major reduction in NADH oxydase activity and in the aunt a diminished level of carnitin compatible with carnitin deficiency. The heterogeneity of these lipidic myopathies is discussed.

Calcium channel activity in a purified dihydropyridine-receptor preparation of skeletal muscle

A purified dihydropyridine-receptor complex (DHPR) of skeletal muscle consisting of a major polypeptide of Mr 150K under reducing conditions induces divalent cation selective channels when incorporated into planar lipid bilayers. Channels were inserted into preformed planar bilayers by two techniques: (i) direct dilution of detergent-solubilized DHPR into the aqueous chambers adjacent to the bilayer membrane or (ii) reconstitution of DHPR into phospholipid vesicles followed by fusion of the preformed vesicles to the planar bilayer membrane. Unlike native membrane preparations of t-tubules, which only have one major Ca channel type of slope conductance of 12 pS in symmetrical 100 mM Ba, the purified DHPR complex induced at least two channel types with conductances of 12-14 and 22 pS. Some recordings suggest that these two channels are statistically coupled in time, i.e., that they may correspond to substrates of the same DHPR channel. Activity was found to occur spontaneously in the absence of the Ca channel agonist Bay k 8644. The 12-14-pS channel from DHPR exhibits voltage-dependent kinetics, is highly selective for barium ions, and was inhibited by micromolar nitrendipine. The 12-14-pS DHPR channel appears to be identical with functional Ca channels previously described in native t-tubules.

Identification of a novel 1,4-dihydropyridine- and phenylalkylamine-binding polypeptide in calcium channel preparations

A 1,4-dihydropyridine- and phenylalkylamine-binding polypeptide has been identified by photoaffinity labeling of purified rabbit and guinea pig skeletal muscle calcium channel preparations. The arylazide ligands (-)-[3H]azidopine and (-)-5-[(3-azidophenethyl)[N-methyl-3H]methylamino]-2-(3,4,5- trimethoxyphenyl)-2-isopropylvaleronitrile [( N-methyl-3H]LU 49888) were used to label 1,4-dihydropyridine- and phenylalkylamine-binding sites, respectively. A single, 155 to 170-kDa polypeptide was specifically labeled by both ligands in rabbit and guinea pig preparations provided that the skeletal muscle membranes used for purification were derived from fresh and not previously frozen and thawed tissue. The photoaffinity labeled polypeptide (termed here alpha 1) is different from the previously described alpha subunit in that it has the identical electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels irrespective of pretreatment either with N-ethylmaleimide or with dithiothreitol. The use of transverse tubular membranes isolated from previously frozen and thawed skeletal muscle results in a purified calcium channel preparation devoid of the alpha 1 subunit. In these preparations proteolytic degradation products of alpha 1 are labeled with both (-)-[3H]azidopine and [N-methyl-3H]LU 49888. Another large molecular weight polypeptide (termed here alpha 2) was also present in every purified calcium channel preparation studied. alpha 2 is distinct from alpha 1 in that reduction with dithiothreitol changes its apparent mass from 160-190 to 130-150 kDa. The alpha 2 subunit is not photoaffinity labeled either with (-)-[3H]azidopine or [N-methyl-3H]LU 49888. These data suggest that two distinct high molecular weight polypeptides (termed alpha 1 and alpha 2) are putative subunits of skeletal muscle calcium channels. Only the alpha 1 subunit contains both 1,4-dihydropyridine and phenylalkylamine receptors. alpha 2 is the same as the previously described alpha subunit (Curtis, B. M., and Catterall, W. A. (1984) Biochemistry 23, 2113-2118), but is neither a 1,4-dihydropyridine- nor a phenylalkylamine-binding protein.

Paradoxical augmentation of (-)Bay K 8644-induced calcium influx by nitrendipine

(-)Bay K 8644 produced a concentration-dependent contraction of porcine coronary artery rings with the maximal contraction at 10(-6) M. Pretreatment of the rings with 10(-6) M nitrendipine inhibited (-)Bay K 8644-induced contraction, while pretreatment with 10(-8) M nitrendipine potentiated the contraction elicited by (-)Bay K 8644. (-)Bay K 8644 (10(-6) M) significantly stimulated Ca2+ influx. Although 10(-8) M nitrendipine never stimulated Ca2+ influx, Ca2+ influx induced by (-)Bay K 8644 was significantly potentiated by pretreatment with 10(-8) M nitrendipine. Pretreatment with 10(-6) M nitrendipine significantly decreased Ca2+ influx in tissues treated with (-)Bay K 8644. Our results suggest that the increased Ca2+ influx might be involved in the mechanisms by which (-)Bay K 8644-induced contraction was potentiated by pretreatment with nitrendipine.

Absorbable polydioxanone suture for venous anastomoses: experimental studies using venography and transluminal angioscopy

Because of their increased tendency to stenosis and spasm and thrombosis, results after venous anastomoses are often unsatisfactory. Nonabsorbable sutures and a continuous suture technique have been suggested to have a negative effect on the compliance of vascular anastomoses. Eighty venous anastomoses were performed with either an interrupted or continuous suture technique, using polypropylene or polydioxanone (PDS) sutures, according to a randomised experimental model. The anastomoses were divided in four groups: (1) Nonabsorbable suture material, continuous suture technique; (2) Nonabsorbable suture material, interrupted suture technique; (3) Absorbable suture material, continuous suture technique; and (4) Absorbable suture material, interrupted suture technique. The morphology of the anastomoses was controlled by venography directly after closure of the wound and at weekly intervals for 2 months and monthly intervals thereafter until 2 years had passed. In 10 cases venography was followed by transluminal angioscopy in the early postoperative period and after 1, 2, 4, 8 and 12 weeks. In the first 2 months moderate and high degree stenoses were found in all 4 groups by venography. After 8 weeks there was a significant decrease in the incidence of stenosis in all groups with the exception of the group, in which continuous nonabsorbable suture had been used. Using angioscopy a marked swelling of the intima at the site of the anastomoses could be detected in the early postoperative period in all experimental groups. After 2 months no significant narrowing could be identified in groups 2, 3 and 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Visceral pleural thickening in asbestos exposure: the occurrence and implications of thickened interlobar fissures

We evaluated fissural (ie, visceral pleural) thickening on radiographs in two asbestos-exposed study populations and a control group. Asbestos workers had an incidence of fissural thickening of 54.5% compared with 16.0% in the unexposed control group, with a strong positive statistical effect due to asbestos exposure beyond that attributable to age. Fissural thickening occurred in 85% of workers with parietal plaques and in 36% without pleural plaques. Fissural thickening occurred in 45% without radiographic evidence of pulmonary fibrosis, but it was very common (85%) in those with pulmonary fibrosis. Data analysis showed that fissural thickening responds more strongly to asbestos exposure than does plaque formation, with 21 years of asbestos exposure needed for a 50% chance of developing fissural thickening, while 31 years of exposure were needed for a 50% chance of forming pleural plaques. From a second group of 57 asbestos workers evaluated clinically, 8 were diagnosed as having asbestosis with radiographically clear lungs and fissural thickening. We conclude that visceral pleural thickening is common in asbestos exposure, that it is related to the years since first asbestos exposure, and that its presence may indicate the presence of pulmonary asbestosis, even with radiographically normal lungs.

Mapping a region associated with Na channel inactivation using antibodies to a synthetic peptide corresponding to a part of the channel

Antibodies to the synthetic peptide (carrier-coupled) corresponding to amino acids 210-223 of the primary sequence of eel Na channel (C1+ peptide) were generated. The antipeptide antibodies were used to identify functional roles as well as the accessibility from the external membrane surface of the C1+ domains. Rabbit antipeptide antibodies bound specifically to the C1+ synthetic peptide and to an eel membrane fraction bearing a high density of Na channels. When applied to the external surface of cultured dorsal root ganglion cells obtained from newborn rats, the antibodies modify Na channel inactivation by shifting the steady-state Na current-inactivation parameter, h infinity, curve to more negative potentials in fast and slow Na currents. The rate of inactivation of the slow channel is shown to be increased. The antibodies do not have a significant effect on activation of the channels. Part of the amino acid sequence corresponding to C1+ peptide is therefore accessible, in the mammalian Na channel, from the external membrane surface and is associated with the inactivation gate.

Effect of a sustained release formulation of diltiazem on the development of atherosclerosis in cholesterol-fed rabbits

Cholesterol-fed rabbits were used to test potential anti-atherosclerotic effects of diltiazem, a calcium antagonist of the benzothiazepine type. Two groups of 7 rabbits each were fed standard laboratory chow supplemented with 1% cholesterol. One group received a 60 mg sustained release diltiazem capsule twice a day and the other group received a placebo capsule twice a day. A third group of control animals were fed an unmodified basal diet under conditions exactly the same as the experimental groups. All groups were studied over a period of 16 weeks. The cholesterol-fed animals showed a marked increase in plasma total cholesterol which was not significantly different for the diltiazem and placebo groups. Plasma calcium levels, blood pressure, and heart rate were also unchanged from the control animals. In the diltiazem-treated animals, 47.5 +/- 10.5% of the aortae showed atherosclerotic lesions; the value for the placebo group was 43.1 +/- 8.1%. Similar results were obtained for the coronary arteries. These results show that diltiazem treatment in the doses employed in this study had no effect on the reduction of atherosclerosis in this animal model.

Photonastic Control of Leaflet Orientation in Melilotus indicus (Fabaceae)

Leaflet orientation in Melilotus indicus (L.) All. Is under photonastic control during the day and nyctinastic control during the night, but also exhibits a diaphototropic (solar-tracking) response. Detached leaves with the two lateral leaflets excised were used to study the solar-tracking capability of the terminal leaflet. Perception of the photonastic excitation is located in the pulvinule. The lower (abaxial) and upper (adaxial) surfaces perceive photonastic excitation, which results in concomitant contraction of the side exposed to light and/or expansion of the opposite side. Steady state laminar elevation is determined by the fluence rates of the light incident simultaneously on the opposite sides. Light sensitivity of the lower side exceeds that of the upper. Response to photonastic excitation of either side is affected by angle of incidence of the light, but angular dependence is restricted to a limited range of angle of incidence, which differs for the two sides. This may be accounted for by the different topography of the two pulvinar surfaces and the localization in them of the light-sensitive tissues.

Suppression of charge movement by calcium antagonists is not related to calcium channel block

The calcium channel-inhibiting drugs nitrendipine and diltiazem represent two important classes of organic calcium antagonists. In the present study, the effect of these drugs on calcium currents and charge displacement currents in bullfrog semitendinosus muscle fibers was examined using a vaseline gap voltage clamp. Nitrendipine (10 microM) reduced the quantity of charge that moved both during the ON phase (QON) and the OFF phase (QOFF) of charge movement. This action appeared to be most selective for QON. However, at this same concentration, nitrendipine had no blocking action on inward calcium currents. In contrast to these findings, diltiazem blocked calcium currents in a concentration-dependent manner, while slightly increasing the quantity of charge moved during QON and QOFF. The enhancement of charge movement by diltiazem resulted from two actions. First, diltiazem shifted the voltage-dependence of charge movement to more negative potentials. Second, diltiazem increased the maximum amount of charge moved.

Transcranial Doppler ultrasound for the assessment of intracranial arterial flow velocity--Part 2. Evaluation of intracranial arterial disease

Transcranial (TC) pulsed Doppler ultrasound was used to evaluate flow velocity within the intracranial basal cerebral arteries in 71 patients with cerebrovascular disease as revealed by arteriography. Abnormalities of the fast-Fourier transformed (FFT) Doppler spectra were used to detect and classify obstructive lesions as well as dilative arteriopathy of the carotid siphon, the middle, anterior, and posterior cerebral arteries, and the basilar artery. Functional stenosis due to large shunting volumes in patients with arteriovenous malformations and in the presence of significant collateralization of extracranial obstructive lesions were similarly diagnosed.

Purification of putative Ca2+ channel protein from rabbit skeletal muscle. Determination of the amino-terminal sequence

A putative Ca2+ channel protein was purified from rabbit skeletal muscle transverse tubules with the combined use of lectin affinity chromatography and ion-exchange chromatography, followed by sucrose density gradient centrifugation. The major component of the purified preparation detected by sodium dodecyl sulfate-gel electrophoresis was a protein of 150 kDa when reduced with 20 mM dithiothreitol and a 191-kDa protein when treated with 20 mM N-ethylmaleimide. Therefore, this protein appears to be identical with the alpha subunit previously described (Curtis, B. M., and Catterall, W. A. (1984) Biochemistry 23, 2113-2118). This protein was purified by preparative sodium dodecyl sulfate-gel electrophoresis, followed by electroelution and/or electroblotting, and its amino acid composition and NH2-terminal sequence were determined. The NH2-terminal sequence is: NH2-Glu-Pro-Phe-Pro-Ser-Ala-Val-X-Ile-Lys-Ser-X-Val-X-Lys-Met-Gln-.

Transcranial Doppler ultrasound for the assessment of intracranial arterial flow velocity--Part 1. Examination technique and normal values

We present the examination technique and normal values of flow velocity from intracranial basal cerebral arteries for a recently developed pulsed Doppler system operating at 2 MHz emitting frequency. Peak systolic, peak diastolic, and mean flow velocity values are analyzed from fast-Fourier transformed (FFT) Doppler spectra at selected depths for 50 presumed normal subjects ranging in age from 22 to 79 years. Interindividual variation is high for peak flow but moderate for mean flow velocity values, which hence are more likely to discriminate normal from abnormal. Flow velocity values within the posterior cerebral artery (PCA) and the basilar artery (BA) are significantly lower than in the anterior cerebral artery (ACA) and the middle cerebral artery (MCA), which is also unique in showing significantly decreasing values with increasing age: calculated mean flow velocities are 47.3 +/- 13.6 and 45.3 +/- 13.5 cm/sec in the ACA, and 58.4 +/- 8.4 and 44.7 +/- 11.1 cm/sec in the MCA in patients less than 40 years and greater than 60 years, respectively, but 34.2 +/- 7.8 and 29.9 +/- 9.3 (PCA) (patients less than 40 years and patients greater than 60 years), and 34.9 +/- 7.8 and 30.5 +/- 12.4 (BA) (patients less than 40 years and patients greater than 60 years). A new scanning system is introduced, which we suggest will reduce interindividual variations and improve the accurate separation of nearby vessels, which are major causes for the comparatively large standard deviations at present.

[CT follow-up of neurocysticercosis treated with praziquantel]

Praziquantel therapy has produced a much better prognosis in neurocysticercosis since 1980. The computed tomographic findings and follow-up study in 4 patients with neurocysticercosis before and after praziquantel therapy are described. The special difficulties of differential diagnosis and further diagnostic procedures are discussed in cases in which calcifications are absent and only solitary foci can be found.

A possible role for the endothelium in porcine coronary smooth muscle responses to dihydropyridine calcium channel modulators

The role of the endothelium in contraction and relaxation produced by the dihydropyridine calcium channel modulators was examined in porcine coronary smooth muscle. The optically pure dihydropyridine calcium agonists (+)-S202-791 and (-)-Bay k 8644 both produced greater contractions in tissues without endothelium compared with tissues with intact endothelium. In contrast, histamine produced the same degree of contraction in tissues with and without endothelium. In the presence of KCl-induced active muscle tone, the optically pure calcium antagonists (-)-R202-791 and (+)-Bay k 8644 and the nitrovasodilator isosorbide dinitrate all produced the same degree of relaxation in tissues with and without endothelium. These results suggest that the endothelium plays an inhibitory role in dihydropyridine-induced contraction. When coronary rings with intact endothelium were pretreated for 60 min with 10 or 100 nM (-)-R202-791, the contraction to subsequent addition of (+)-S202-791 was significantly greater than in control tissues pretreated with only solvent. However, in rings with denuded endothelium, pretreatment with (-)-R202-791 resulted in a rightward shift of the dose-response curve to (+)-S202-791, and a depression of the maximal contraction compared with controls. Thus, the interaction between the calcium agonist [(+)-S202-791] and antagonist [(-)-R202-791] is more complex than competitive inhibition. We suggest that the calcium agonists produce two effects, a release of endothelium-derived relaxant factor and a direct contraction of smooth muscle; the calcium antagonists can inhibit both processes.(ABSTRACT TRUNCATED AT 250 WORDS)