Personality disorders in dysthymia and major depression.

OBJECTIVE: The purpose of the present study was to investigate the comorbidity of personality disorders in patients with primary dysthymia compared to those with episodic major depression. METHOD: A total of 177 out-patients with primary dysthymia and 187 outpatients with episodic major depression were administered a structured diagnostic interview for DSM-III-R Axis II disorders. In addition, all of these patients completed the BDI, and those with the appropriate level of education also completed the Minnesota Multiphasic Personality Inventory (MMPI). RESULTS: A significantly higher proportion of dysthymic patients than patients with major depression met the criteria for a personality disorder, for borderline, histrionic, avoidant, dependent, self-defeating types and for personality disorders of clusters B and C. Further analysis revealed that the above differences were mainly due to the subgroup of patients with 'early-onset dysthymia'. Finally, patients with a personality disorder, both dysthymics and those with major depression, had significantly higher scores on the BDI and on the majority of the MMPI scales compared to those without a personality disorder. CONCLUSION: The data indicated that (i) dysthymia--mainly that of early onset--is associated with significantly higher personality disorder comorbidity than episodic major depression, and (ii) the presence of a personality disorder is related to more severe overall psychopathology.

Receptor crosstalk: effects of prolonged carbachol exposure on beta 1-adrenoceptors and adenylyl cyclase activity in neonatal rat ventricular myocytes.

Supersensitivity of adenylyl cyclase after exposure to inhibitory agonists is a general means of cellular adaptation. We hypothesized that such "crosstalk" between muscarinic cholinergic agonists, beta 1-adrenoceptors, and adenylyl cyclase may be an important mechanism of cardiac adaptation to interventions that enhance vagal activity. We used primary cultures of neonatal rat ventricular myocytes and measured beta-adrenoceptors by radioligand binding and adenylyl cyclase activity by a single column method. Carbachol induced a time- and dose-dependent reversible decrease in cell surface beta 1-adrenoceptors. The peak effect occurred after 20 h of exposure to 100 microM carbachol which caused a decrease in the maximum number of binding sites for the beta-adrenoceptor antagonist 3H-CGP-12177 from 42.3 +/- 3.4 to 33.0 +/- 2.6 fmol/mg protein (n = 12, P < 0.03) without a change in antagonist affinity. Loss of cell surface receptors was prevented by atropine and by the protein kinase C inhibitor H7. The decrease in cell surface receptors was not accompanied by receptor internalization as assessed by equilibrium binding experiments in a cytosolic fraction using 125I-iodocyanopindolol. In contrast to the well-known acute inhibitory effects of carbachol on adenylyl cyclase activation, prolonged carbachol exposure preserved (-)-isoprenaline-stimulated adenylyl cyclase activity and enhanced postreceptor stimulated adenylyl cyclase activity. Carbachol did not further enhance adenylyl cyclase activity after pretreatment with pertussis toxin. The protein kinase C inhibitor chelerythrine prevented the carbachol induced enhancement of forskolin-stimulated adenylyl cyclase activity. We conclude that prolonged incubation with carbachol in rat neonatal ventricular myocytes causes a reduction in cell surface beta 1-Adrenoceptor density. beta 1-Adrenoceptor-mediated adenylyl cyclase activity is preserved and postreceptor-mediated adenylyl cyclase activity is augmented. Our data suggest that carbachol-stimulated protein kinase C activity may play a key role in the prolonged muscarinic regulation of adenylyl cyclase activity.

A phorbol ester augments cAMP content and adenylyl cyclase activity in neonatal rat cardiac myocytes despite reduced beta adrenoceptor density.

OBJECTIVES: In cultured neonatal rat myocardial cells the phorbol ester, phorbol-12 myristate 13-acetate (PMA), was used as a probe to examine the short term effects of augmented protein kinase C activity on the adenylyl cyclase system and on beta adrenoceptors. METHODS: beta Adrenoceptors were measured by radioligand binding, cAMP by radioimmunoassay, and adenylyl cyclase activity by a single column method. RESULTS: After 10 minutes of incubation with 100 nM PMA beta adrenoceptor density was reduced by 25% (p < 0.002) with no change in antagonist affinity. Competition curves showed no increase in agonist affinity for (-)-isoprenaline. Surprisingly, cAMP content stimulated by 1 microM (-)-isoprenaline increased by 62% from 47 (SEM 6) to 76(15) pmol.100 microliters-1 (n = 8, p < 0.05). Both effects could be suppressed by incubation with the protein kinase C inhibitor 1-(5-isoquinoline-sulphonyl)-2-methylpiperazine dihydrochloride (H7). Preincubation with PMA also augmented NaF, Mn2+, and forskolin stimulated adenylyl cyclase activity but had no effect on guanylyl-5'-imidodiphosphate (GppNHp) stimulated enzyme activity over a wide range of concentrations. PMA did not alter the effects of pertussis toxin on (-)-isoprenaline-stimulated cAMP content. CONCLUSIONS: These data indicate that protein kinase C modifies both the catalytic subunit of adenylyl cyclase and the guanine nucleotide stimulatory protein (Gs), and also suggest that NaF and GppNHp act at different sites on Gs alpha. PMA enhances adenylyl cyclase responsiveness despite loss of beta adrenoceptors in cultured neonatal rat ventricular myocytes. These findings suggest that Ca2+ and phospholipid dependent protein kinase C acting at multiple sites in the beta adrenoceptor-adenylyl cyclase cascade may be involved in the regulation of cAMP concentrations in myocardial cells.

The clinical spectrum of patients with aneurysms of the ascending aorta.

Aneurysms of the ascending aorta are often unsuspected, yet they can quickly lead to death from aortic rupture or dissection. To examine the clinical spectrum of patients with aneurysms of the ascending aorta, we searched the University of California, San Francisco (USCF) Echocardiography Data Base for all patients with aneurysms of the ascending aorta (> or = 5.0 cm in diameter) seen over a 7-year period. The echocardiograms and clinical courses of these patients were then reviewed. We identified 15 patients with aneurysms of the ascending aorta: five had aneurysms > 7.0 cm in diameter, three had aneurysms 6.0 to 6.9 cm, and seven had aneurysms 5.0 to 5.9 cm in diameter. Among the five patients < 50 years of age, four had Marfan's syndrome, and among the 10 patients > or = 50 years of age, eight had evidence of atherosclerotic vascular disease. At presentation, 13 patients had nonspecific symptoms, and two were asymptomatic. Echocardiography demonstrated that 12 patients had at least mild aortic insufficiency and that five had aortic dissections. One of the seven patients who underwent surgical resection died of an intraoperative cardiac arrest, and two of the eight patients treated medically died within 1 week of presentation. We conclude that the clinical spectrum of patients with aneurysms of the ascending aorta is wide. Because these aneurysms are often unsuspected, physicians should have a low threshold for imaging the ascending aorta in patients with Marfan's syndrome or atherosclerotic vascular disease, particularly when aortic insufficiency is present.

Haloperidol- and SCH23390-induced dopaminergic supersensitivities are not additive in the rat.

The effect of chronic D-1 and/or D-2 dopamine receptor blockade on apomorphine-induced behaviors was studied in rats treated for 21 days with the selective D-1 antagonist SCH23390, the predominantly D-2 antagonist haloperidol, and the combination of the two drugs at the same daily doses (0.1 and 1 mg/kg respectively). Apomorphine (0.3 mg/kg) 4 days following the last injection of the drugs increased (49-70%) stereotypic behavior in all animals as compared to saline-treated controls. Although the SCH23390-induced increase was lower than haloperidol-induced supersensitivity, stereotypies after combined administration of both drugs did not differ significantly from either, suggesting that the effects of the two drugs are not additive. Underlying receptor changes and modified D-1/D-2 receptor interactions may account for the participation of both receptor subtypes to the development of neuroleptic-induced dopaminergic supersensitivity.

Anatomical observations on the arcade of Frohse and other structures related to the deep radial nerve. Anatomical interpretation of deep radial nerve entrapment neuropathy.

In a series of 120 elbow regions (66 male, 54 female) from embalmed human cadavers, the authors observed the course of the deep radial nerve and then related it to structures such as a) the deep surface of the initial part of the extensor carpi radialis brevis, which was found to be tendinous in 90% of the cases, b) the superior hiatus of the supinator muscle, which formed a fibrous arcade of Frohse in 61% of the cases, and the distance of its peak from the lateral condyle, which ranged from 4 to 6 cm, and c) the angle between the superficial oblique muscle fibres of the supinator and the long axis of the radius, which varies from 18 degrees to 38 degrees and crossed the nerve almost transversely. The above anatomical factors--and particularly the thickened fibrous arcade of Frohse--are all important for the deep radial entrapment neuropathy in predisposed individuals.

Absorption filtration. A tool for the measurement of ion tracer flux in native membranes and reconstituted lipid vesicles.

A rapid, simple and reproducible method has been developed for the measurement of ion tracer flux with both native membrane vesicles and reconstituted lipid vesicle systems. Following the absorption of vesicles onto glass fiber filters, tracer flux is performed directly upon the deposited samples. In contrast to the more conventional vacuum and gel filtration techniques, absorption filtration exhibits comprehensive data retrieval whereby the removal of extravesicular ions, the retention of intravesicular ions and the amount of ions fluxed can be accurately analyzed. Both influx and efflux assays have been designed to measure the carbamylcholine-induced flux of 22Na+ which is characteristic of acetylcholine receptor-enriched membranes from Torpedo californica electroplax. The flux signal-to-background noise ratio is maximized in the efflux assay, since agonist activation is performed subsequent to the exhaustive removal of extravesicular tracer. An interesting feature of the influx assay is that the agonist-induced uptake of 22Na+ can be repeated with the original vesicles which additionally maximizes the flux signal. With either approach, the inactivation of ionophoric activity due to prolonged exposure to agonists ('desensitization') can be reversed upon removal of agonist without dilution of the deposited samples. Due to the large array of glass fiber filters and ion-exchange disks, the absorption filtration technique should be able to accommodate the transport and binding of soluble molecules to a variety of intact cells, membranes and reconstituted lipid vesicles.

Acetylcholine receptor from Torpedo. Preferential solubilization and efficient reintegration into lipid vesicles.

The acetylcholine receptor has been effectively solubilized from Torpedo californica electroplax under defined conditions with the nonionic detergent, beta-D-octylglucopyranoside. Preferential solubilization of the receptor protein, with regard to yield and specific alpha-bungarotoxin binding activity, occurs in the absence of salt and diminishes when NaCl is present in the solubilization media (greater than or equal to 50 mM). Conversely, elevated salt concentrations increase the solubilization of bulk membrane proteins including the peripheral membrane enzyme, acetylcholine esterase. Additional selectivity for the solubilization of acetylcholine receptor can be obtained by adjusting the detergent to membrane phospholipid molar ratio within a narrow optimum range (4.1 to 6.7). Purified acetylcholine receptor and electroplax total lipid are utilized to reconstitute chemically excitable membrane vesicles. Reconstitution is achieved by dialysis of octylglucopyranoside from lipid/detergent/receptor protein mixed micelles and the resulting vesicles are analyzed by sucrose density gradient centrifugation. Extensive incorporation of the acetylcholine receptor within the lipid vesicles is obtained at lipid concentrations greater than 18 mg/ml with lipid/protein ratios ranging from 12/1 to 60/1 (w/w). Reconstituted receptor vesicles and native receptor-enriched membranes exhibit similar agonist-induced effluxes of 22Na+ with 50% of the maximum response occurring at carbamylcholine concentrations of 1.8 X 10(-5)M and 3.4 X 10(-5)M, respectively. At saturating carbamylcholine concentrations (10(-2)M) the agonist-induced efflux of 22Na+ for both native and reconstituted acetylcholine receptor is (6-7) X 10(13) cpm 22Na+ per mol of receptor. The efflux responses exhibited by either preparation can be effectively blocked by preincubation with carbamylcholine ('desensitization'). The similar behavior of native and reconstituted acetylcholine receptor indicates that octylglucopyranoside-purified receptor retains all of the necessary determinants for proper ligand binding and ion translocation.

Characterization of acetylcholine receptor isolated from Torpedo californica electroplax through the use of an easily removable detergent, beta-D-octylglucopyranoside.

Non-ionic detergents used for the solubilization and purification of acetylcholine receptor from Torpedo californica electroplax may remain tightly bound to this protein. The presence of detergent greatly hinders spectrophotometric and hydrodynamic studies of the receptor protein. beta-D-Octylglucopyranoside, however, is found to be effective in solubilizing the receptor from electroplax membranes with minimal interference in the characterization of the protein. The acetylcholine receptor purified from either octylglucopyranoside- or Triton X-100-solubilized extracts exhibits identical amino acid compositions, alpha-Bungarotoxin and (+)-tubocurarine binding parameters, and subunit distributions in SDS-polyacrylamide gels. The use of octylglucopyranoside allows for the assignment of a molar absorptivity for the purified receptor at 280 nm of approx. 530000 M-1 . cm-1. Additionally, successful reconstitution of octylglucopyranoside-extracted acetylcholine receptor into functional membrane vesicles has recently been achieved (Gonzales-Ros, J.M., Paraschos, A. and Martinez-Carrion, M. (1980) Proc. Natl. Acad. Sci. U.S.A. 77, 1796--1799). Removal of octylglucopyranoside by dialysis does not alter the specific toxin and antagonist binding ability of the receptor or its solubility at low protein concentrations. Sedimentation profiles of the purified acetylcholine receptor in sucrose density gradients reveal several components. Sedimentation coefficients obtained for the slowest sedimenting species agree with previously reported molecular weight values. Additionally, the different sedimenting forms exhibit distinctive behavior in isoelectric focusing gels. Our results suggest that both the concentration and type of detergent greatly influence the physicochemical behavior of the receptor protein.

Side effects in preventive maintenance therapy with neuroleptics with special emphasis on tardive dyskinesia.

Neuroleptics induce hypersensitivity reactions, and toxic, systemic and extrapyramidal manifestations. The latter mainly include acute dystonic reactions, other early dyskinesias, akathisia, parkinsonism and TD. These drugs have been implicated for DA antagonism exerted by an adenylate cyclase inhibition. Prolonged blockade of DA receptors is considered as the motivation for a counterbalancing mechanism inducing the DA supersensitivity from which TD results. Recent reports suggest cholinergic and GABA ergic insufficiency as secondary participants. The increasing frequency of TD calls for prevention by modifying treatment practices and searching for effective measures to combat the symptoms.

Reconstitution of functional membrane-bound acetylcholine receptor from isolated Torpedo californica receptor protein and electroplax lipids.

Purified acetylcholine receptor and total lipids, both extracted from Torpedo californica electroplax, were utilized to reconstitute chemically excitable membrane vesicles. Reconstitution was achieved by dialysis of the extraction detergent, octyl beta-D-glucoside from protein/lipid incubation mixtures. The reconstituted preparations could be fractionated by sucrose density gradient centrifugation and consisted of vesicular structures visible in electron micrographs. In addition, the reconstituted vesicles exhibited;the following properties characteristic of native receptor-enriched membranes: (i) an external distribution of alpha-bungarotoxin-binding sites, (ii) a time-dependent binding of alpha-bungarotoxin that is depressed by preincubation with the cholinergic agonist carbamoylcholine ("desensitization"), (iii) an ability to retain 22Na+ that is lost in the presence of detergents or gramicidin A, and (iv) a carbamoylcholine-induced acceleration of 22Na+ efflux that can be blocked by alpha-bungarotoxin. The purified acetylcholine receptor that was utilized in the reconstitution experiments apparently does not require other protein components for ligand recognition or ion translocation.