Interaction with 14-3-3 proteins promotes functional expression of the potassium channels TASK-1 and TASK-3

The two-pore-domain potassium channels TASK-1, TASK-3 and TASK-5 possess a conserved C-terminal motif of five amino acids. Truncation of the C-terminus of TASK-1 strongly reduced the currents measured after heterologous expression in Xenopus oocytes or HEK293 cells and decreased surface membrane expression of GFP-tagged channel proteins. Two-hybrid analysis showed that the C-terminal domain of TASK-1, TASK-3 and TASK-5, but not TASK-4, interacts with isoforms of the adapter protein 14-3-3. A pentapeptide motif at the extreme C-terminus of TASK-1, RRx(S/T)x, was found to be sufficient for weak but significant interaction with 14-3-3, whereas the last 40 amino acids of TASK-1 were required for strong binding. Deletion of a single amino acid at the C-terminal end of TASK-1 or TASK-3 abolished binding of 14-3-3 and strongly reduced the macroscopic currents observed in Xenopus oocytes. TASK-1 mutants that failed to interact with 14-3-3 isoforms (V411*, S410A, S410D) also produced only very weak macroscopic currents. In contrast, the mutant TASK-1 S409A, which interacts with 14-3-3-like wild-type channels, displayed normal macroscopic currents. Co-injection of 14-3-3ζ cRNA increased TASK-1 current in Xenopus oocytes by about 70 %. After co-transfection in HEK293 cells, TASK-1 and 14-3-3ζ (but not TASK-1ΔC5 and 14-3-3ζ) could be co-immunoprecipitated. Furthermore, TASK-1 and 14-3-3 could be co-immunoprecipitated in synaptic membrane extracts and postsynaptic density membranes. Our findings suggest that interaction of 14-3-3 with TASK-1 or TASK-3 may promote the trafficking of the channels to the surface membrane.     

The heparin management test: a new device for monitoring anticoagulation during coronary intervention

Whole blood coagulation analysers are widely used during percutaneous coronary interventions. The precise degree of anticoagulation in patients is important in this setting. The aim of this investigation was to compare the results obtained with ACT (Hemochron) and HMT, the Heparin Management Test (TAS) in patients undergoing percutaneous coronary interventions. Patients (n=100) were enrolled prospectively. Each patient received 10,000 units of heparin. At the end of the procedure, the mean ACT was 284±31 seconds and the mean HMT was 292±33 seconds. The correlation between the two methods was highly significant (r=0.64, p<0.001). The HMT correlates well with ACT values in patients undergoing percutaneous coronary interventions. Its use in the management of these patients should be considered.     

Diode laser thermokeratoplasty – first clinical experience

Purpose: Pulsed holmium lasers are currently used to correct hyperopia by means of laser thermokeratoplasty (LTK). Series of μs laser pulses are applied with a high repetition rate to induce shrinkage of corneal collagen fibers. The pulsed energy application results in intrastromal temperature peaks of up to 200 °C. A continuously emitting laser diode can – as we demonstrated recently in an invivo study on minipigs – be used for LTK and may be of advantage because the temperature rise is more steady. The aim of this study was to examine the safety, amount, and stability of hyperopic correction of diode LTK on blind human eyes. Methods: We used a laserdiode that was set to continuously emit light at λ = 1.854 μm/μ_a = 1.04 mm^–1(group I, n = 4) or 1.87 μm/μ_a = 1.92 mm^–1 (group II, n = 4). Radiation energy was 100 to 150 mW for 10 s per coagulation. Eight coagulations on a single ring (group I) and 16 coagulations on a double ring (group II) diameter were applied in the cornea concentric to the entrance pupil by means of a vacuum-fixed application mask (group I = conjunctival fixation; group II = corneal fixation) and a handpiece with a focusing optic. Preoperatively as well as 1 week, 1, 2, 3, 6 12 and 18 months postoperative ophthalmologic controls were performed and the corneal refractive power was measured. Results: In group I initial refractive changes of up to + 4.9 D were achieved (1 week postoperative). However, due to the great penetration depth of the laser irradiation, large endothelial defects resulted beneath the stromal coagulations. In group II an initial refractive change of up to + 6.8 D was achieved and as a result of the reduced penetration depth, the endothelial cell damage was much reduced. Partial regression of the refractive effect occured in all subjects, which continued in higher refractive changes during the 2^nd postoperative year. The refractive effect at 12 months was + 0.6 to + 1.5 D in group I and + 0.9 to + 5.7 D in group II. At 12 months the induced astigmatism was 0.5 to 2.2 D in group I and 0.3 to 1.6 D in group II. No serious adverse effects were noticed. Conclusion: A continously emitting laser diode working at a wavelength of 1.87 μm can be used to correct hyperopia by means of LTK safely and effectively. Regression occurs predominantly in the first 6 postoperative months. Further studies must be conducted to determine the importance of patient inherent parameters such as age in establishing a nomogram.      

Neuroleptic malignant syndrome during low dosed neuroleptic medication in first-episode psychosis: a case report

 Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal side-effect of antipsychotic drug therapy, especially of dopamine receptor antagonists. As a dose relationship has been postulated, low dose neuroleptization would be expected to help to avoid this side-effect. In contrast, we report on a 21-year-old female following low dose fluphenazine treatment with 2.5 mg/day. The patient recovered from NMS after 3 days of dantrolene administration. Eventually, remission from psychotic symptoms was achieved with clozapine. At 8-month follow-up, psychopathology remained stable and there were no more signs of NMS. Received: 8 July 1998 / Final version: 6 November 1998     

Cognitive functioning in female patients with 21-hydroxylase deficiency

The cognitive functioning of 27 female patients with congenital adrenal hyperplasia (CAH) (aged 11–41 yrs) and 13 of their healthy sisters (13–31 yrs) was compared using short versions of age-appropriate Wechsler scales. In contrast to other studies, neither a higher than average IQ level for CAH patients (mean: 99.0) nor for their sisters (97.7) was found. Unexpectedly, and in contrast to other reports, the subgroup of salt-wasting (SW) patients>16 yrs (N=6; mean score: 111.5) differed from their sisters as well as from simple-virilizing (SV) patients in full IQ (p<0.05) and subtest scorings for Information, Similarities, and Picture Completion (p<0.05–<0.10). SW patients displayed more masculine behaviour (vs. SV patients and sisters) which, in turn, was related to differential prenatal hormonal influences. No clear-cut relationships between IQ/cognitive (subtest) findings and gender-role behaviour were found.

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Zusammenfassung 27 Patientinnen mit dem Adrenogenitalen Syndrom (AGS) (11–41 J.) und 13 ihrer Schwestern (13–31 J.) wurden hinsichtlich intellektueller Funktionen verglichen (Kurzformen von HAWIK, HAWIE). Im Unterschied zu den meisten früheren Untersuchungen wurden weder für Patientinnen (mean: 99.0) noch für Kontrollen (97.7) über dem Durchschnitt liegende IQ-Werte gefunden. Im Gegensatz zur Literatur unterschied sich die Teilgruppe der Salzverlust-Patientinnen (SW)>16 J. (N=6, mean: 111.5) von den Schwestern und den Patientinnen mit einfachem AGS (SV) im Gesamt-IQ (p<0.05) und in den Untertests Allgemeines Wissen, Gemeinsamkeiten und Bilderergänzen (p<0.05–<0.10). SW-Patientinnen hatten signifikant männlichere Verhaltensmuster gezeigt (vs. SV-Patientinnen und Schwestern), die auf differentielle Hormoneffekte pränatal bezogen worden waren. Es fanden sich aber keine klaren Zusammenhänge zwischen IQ-bzw. Untertest-Resultaten und Ergebnissen für Geschlechtsrollenverhalten.

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Résumé Le fonctionnement cognitif de 21 patientes avec une hyperplasie congénitale surrénale (âgée de 11 à 41 ans) et de 13 de leurs soeurs saines (13–31 ans) a été comparé au moyen de versions raccourcies de l'échelle de Wechsler appropriée à l'âge. En contraste avec d'autres études, il n'a été retrouvé un Q.I. plus haut que la moyenne ni pour les patientes (moyenne 99.0) ni pour leurs soeurs (moyenne 97.7). De façon inattendue, et en contraste avec d'autres études, le sous-groupe de patientes déprivées en sel (SW)>16 ans (N=6), moyenne score: 111.5) différait de leurs soeurs aussi bien en tant que patientes présentant des signes de virilsation (SV) pour le Q.I. complet (p<0.05) et les scores aux subtests d'information, de similarité et de complément d'images (p<0.05–0.10). Les patientes déprivées en sel (SW) montraient un comportement plus masculin (vs. SV et leurs soeurs) qui en retour était relié aux influences hormonales prénatales différentes. Il n'y avait pas de relation de différences nettes entre les résultats aux sous-tests cognitifs du Q.I. et le comportement de genre.

     

Operative mortality, mortality and late results in bronchial carcinoma]

457 patients with a bronchial carcinoma of the years 1947--1962 are compared with 126 patients of the years 1969--1970 and set up in comparison to the whole clinical material of the years 1960--1975. In the period between 1969 and 1970 radical resections were performed in 20% more patients than in the first period (1947--1962). Older patients were in the last period (1970--1974) more frequent. 8% of all patients in which lobectomy was performed and 5.5% of the patients in which pneumonectomy was performed were older than 70 years of age. Overall mortality has remained unchanged for exploratory thoracotomy (19%), palliative resection (17.5%) and "radical" resection (14%). For simple pneumonectomy the overall mortality went down from 19.2% (1960--1964) to 9.6% (1970-1974) and for simple lobectomy from 14.4% to 3.8%. The five-year survival rate after radical resections was 8% (first period 0%) and after simple resections 26% (26.2%). Patients with stage I epidermoid carcinoma had a five-year survival rate of 46%. Those with stage II (spread to ipsilateral hilar nodes) a five-year survival rate of 14.3% Patients with palliative resections and exploratory thoracotomy died within 16 months.     

Polyhalogenated dibenzo-p-dioxins and dibenzofurans and the immune system

We used a modified version of the popliteal lymph node assay in rats to investigate the immunosuppressive potential of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In 10 months we conducted 3 experimental series. Animals were treated with single s.c. injections of TCDD and 7 days later human red blood cells (HRBC) were injected s.c. into the right hind footpad of the rat. Another 7 days later, both popliteal lymph nodes were prepared, weighed, the cell number was counted and the quotients (index) of these variables from the treated and the untreated side were determined. The doses applied in three experimental series were 600, 60, 6, 0.6, and 0.06 ng TCDD/kg body wt. In the first experimental series only the three highest doses were tested, in a second experimental series doses of 60, 6, 0.6, 0.06 ng TCDD/kg body wt were applied. Combining the results of these two experimental series, a statistically significant difference was found in the cell number index between the controls and the two highest doses tested (60 and 600 ng/kg body wt;p <0.01). This result was recently published as an abstract (Korte et al. 1990). However, with slight methodological changes in the third series of experiments (doses applied: 600, 60, 6, 0.6, and 0.06 ng TCDD/kg body wt) and using a greater number of animals we could not confirm these preliminary results. No difference was seen in the immune response to the antigen challenge in controls and in any of the treatment groups. We conclude that TCDD does not clearly influence the immune response as observed in the popliteal lymph node assay under our experimental conditions.     

Reproductive toxicity and toxicokinetics of 2,3,7,8-tetrachlorodibenzo-p-dioxin

Possible effects on the next generation after long-term exposure (subcutaneous administration) of male rats to very high doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were studied. Two dose regimes were applied: TCDD-25 (initial dose: 25 g/kg body wt; maintenance dose: 5 g/kg body wt, once weekly) and TCDD-75 (initial dose: 75 g/kg body wt; maintenance dose: 15 g/kg body wt). Male rats were treated for 10 weeks before mating and then throughout the entire 12 week mating period. They were mated to unexposed virgin females. One group of pregnant females was used for teratological evaluations, and another group was allowed to deliver. No significant differences were observed in the number of implantations or fetuses per litter, and resorption rate, and fetal weight between the controls and TCDD-treated groups. No gross-structural anomalies occurred in any of the fetuses sired by TCDD-treated males. In the TCDD-25 group an increased frequency of two types of variations was observed which also occur in controls: incompletely ossified fingers (TCDD-25=5.1%, controls=2.6%), and incompletely ossified ossa zygomatica (TCDD-25=1.8%, controls=0.5%). In the TCDD-25 group a slight but statistically significant increase was observed in the rate of stillbirths (TCDD-25=1.3%, controls=0.1%), apparently due to an unusually low frequency occurring in the controls (overall historical controls=0.6%). There was no difference in postnatal mortality (TCDD-25=1.3%, controls=1.3%). Taken together, despite the very high doses of TCDD used, the data do not provide evidence for biologically significant paternally-mediated developmental toxicity in the fetuses and newborn.