Effects of electroconvulsive therapy (ECT) on thyroid function parameters

Serum concentrations of thyroxine, triiodothyronine, TSH and prolactin were measured in 10 patients with affective disorders receiving ECT. Samples were drawn at -15 min, 0, +30 min, +60 min and +3 hr after ECT. A significant increase in both prolactin and TSH was observed 30 min after ECT. A small but significant decrease in triiodothyronine but no change in thyroxine was found in all post-ECT samples. The increase in TSH may be caused by an anti-dopaminergic effect of ECT at either the pituitary or the hypothalamic level.     

Repression of mRNA for the PLK cell cycle gene after DNA damage requires BRCA1

DNA damage activates the G2 cell cycle checkpoint to allow time for DNA repair before mitotic entry. The mechanism involves inhibition of the enzymatic activity for polo-like kinase 1 (Plk1), rendering Cdc25C with a basal phosphatase activity that is insufficient for converting Cdc2 to the fully active G2/M transition kinase. We found that cell cycle arrest at the G2/M boundary after ionizing radiation (IR) of breast carcinoma cells may involve repression of the gene for Plk1, PLK, mediated by the tumor-suppressor protein BRCA1. The p53-defective MT-1 cell line had an apparent accumulation of G2/M phase cells 12 h after irradiation. This response was preceded by a transient downregulation of PLK mRNA expression with a barely detectable level 6 h after exposure to IR but recovered after 12 h. A significantly lower fraction of irradiated BRCA1(-/-) HCC1937 cells arrested in the G2/M phase after 12 h, and the transient response of PLK mRNA was also considerably impaired. After reconstitution of wild-type BRCA1 in the HCC1937 cells however, downregulation of PLK mRNA as well as Plk1 protein expression after IR was restored. Moreover, the suppression of PLK mRNA expression 6 h after irradiation was completely abolished by the specific CHEK1 kinase inhibitor UCN-01, further indicating that the effector mechanism of DNA damage on PLK signals through BRCA1 and its downstream CHEK1. Our observations provide new information about the diversity of regulatory mechanisms governed by BRCA1 in DNA damage checkpoint control.     

Doxazosin GITS compared with doxazosin standard and placebo in patients with mild hypertension

Doxazosin, an effective treatment for mild-to-moderate hypertension and benign prostatic hyperplasia, in its standard formulation requires a multiple-step titration regimen to minimize the potential for first-dose effects. A new controlled-release gastrointestinal therapeutic system (GITS) formulation of doxazosin was developed to enhance the pharmacokinetic profile, significantly reducing serum peak-to-trough ratios, thereby minimizing the need for titration. We assessed the efficacy and tolerability of doxazosin GITS compared with doxazosin standard and placebo in a prospective, randomized, double-blind, parallel-group, dose-titration, multicenter study of 392 patients with mild hypertension (blood pressure [BP] < or = 180/95-105 mmHg). Patients were randomized to doxazosin GITS, doxazosin standard, or placebo in 2:2:1 manner. The primary outcome measure was the proportion of patients in the per-protocol analysis (PPA) who achieved goal BP response (sitting BP < or = 90 mmg or 10 mmHg decrease from baseline at 24 h postdose at the final evaluable visit). Goal BP response in the intention-to-treat (ITT) population and prespecified BP and/or heart rate changes in the PPA and/or ITT population were also analyzed. Tolerability was assessed throughout the study. Doxazosin GITS and doxazosin standard produced comparable goal BP responses superior to that of placebo, with 92 of 156 patients (59.0%) on doxazosin GITS and 86 of 152 patients (56.6%) on doxazosin standard in the PPA population achieving goal BP response 24 hours postdose on the final visit, compared with 25 of 70 patients (35.7%) on placebo. Both active treatments produced mean significant BP reductions compared with baseline and placebo (p < 0.001). The most commonly reported side effects were headache, dizziness, and asthenia. No syncope was reported in the doxazosin GITS group; two cases were observed in the doxazosin standard group and one case in the placebo group. Doxazosin GITS was well tolerated and as effective as doxazosin standard in patients with mild hypertension, producing well-tolerated, comparable BP reductions with minimal need for titration. Both active treatments were clinically and statistically superior to placebo.     

Functional properties of CD19+ B lymphocytes positively selected from buffy coats by immunomagnetic separation.

Here we report that human B lymphocytes can be positively selected directly from buffy coats applying the anti-CD19 antibody AB1 coupled to magnetic beads. This isolation protocol is highly efficient and the isolated cell population is of very high purity and viability. As judged by cell cycle analysis and various parameters for cell activation, the cells are still in a resting state after isolation. Furthermore, different functional assays have shown that the isolation procedure does not interfere with either activation or proliferation/differentiation of CD19 selected cells as compared to negatively isolated cells. As a consequence of cross-linking during the isolation process, the CD19 antigen is temporarily down-regulated as measured by AB1 binding. Despite this decreased expression, monoclonal antibodies to the CD19 antigen nevertheless inhibited anti-mu plus B cell growth factor induced B cell activation as reported also for negatively isolated cells. Taken together, the presented data strongly suggest that B cells isolated through the CD19 antigen can be used in critical functional assays.     

Mechanism of osmotic diuresis studied by infusion of NaHCO3 and mannitol in dogs

To examine whether mannitol and NaHCO3 are equally potent inhibitors of proximal tubular fluid reabsorption, experiments were performed in 10 anaesthetized volume-expanded dogs during continuous infusion of ethacrynic acid. At plasma pH 7.5, a rise in plasma osmolality of 40 mosmol kg-1 reduced the remaining tubular fluid reabsorption in five dogs by 14 +/- 3% during NaHCO3 infusion and by 28 +/- 1% during mannitol infusion. Bicarbonate reabsorption increased by 25 +/- 5% during NaHCO3 infusion and decreased by 14 +/- 1% during mannitol infusion. At equal rates of bicarbonate reabsorption the inhibitory effects on tubular fluid and NaCl reabsorption were slightly less during mannitol than during NaHCO3 infusion. In five other dogs studied at constant plasma concentration of sodium, changes in bicarbonate reabsorption were avoided by raising plasma pH to 7.7 during NaHCO3 infusion and by reducing plasma pH to 7.4 during mannitol infusion. Tubular fluid reabsorption was reduced 32 +/- 4% by NaHCO3 and 34 +/- 4% by mannitol infusion, indicating equal inhibitory effects. The mechanism may be that the osmotic force for paracellular reabsorption of water and NaCl across the tight junction is equally reduced by equiosmolal increments in the NaHCO3 and mannitol concentration of the proximal tubular fluid.     

CQP 201-403, a new dopamine agonist in the treatment of hyperprolactinemia

Current drugs used for hyperprolactinemia may have severe side effects. Effects and side effects of a new propylergoline derivate (CQP 201-403 SANDOZ) have been evaluated. Twenty-four otherwise healthy women (21-44 years) with hyperprolactinemia (35-318 micrograms/l) without extrasellar extension of pituitary adenomas took part in a randomized, double-blind study. Fasting prolactin levels measured on day 7 was significantly decreased when compared with day 1 (P less than 0.05) in all CQP groups, to 78% with 0.005 mg daily, to 40% with 0.015 mg daily, and to 27% with 0.025 mg CQP per day for one week. The levels in the control group did not change (96%). The area under the curve of the prolactin day curve (1-8 h after drug administration) decreased significantly (P less than 0.05) at all doses when day 7 was compared with day 1, to 77% with 0.005 mg, to 51% with 0.015 mg, and to 37% with 0.025 mg CQP. No change was seen in the control group (96%). Four patients (one on 0.005 mg, one on 0.015 mg, and two on 0.025 mg) experienced orthostatic hypotension while standing blood pressure was to be measured on the first day of treatment, and they had to lie down. CQP 201-403 lowers prolactin levels in hyperprolactinemic women at all doses employed. The effect was seen after the first dose of treatment, and lasted for at least 24 h. The adverse reactions are few and tolerable, and might be less than with current bromocriptine therapy.     

Double-blind comparison of tiapamil and atenolol in patients with mild to moderate hypertension: A multicenter trial

Summary The efficacy and safety of tiapamil, a new calcium-channel blocker, was compared with the cardio-selective beta-blocker atenolol in a 16-week double-blind, multicenter trial with an initial 4-week placebo run-in period. Eighty-one outpatients with WHO stage I or II hypertension, 55 men and 26 women, entered the study. There was a total of nine drop-outs, six in the tiapamil group and three in the atenolol group. Five were due to side effects (four in the tiapamil group and one in the atenolol group). Sixty-one patients performed a graded exercise test sitting on a ergometer bicycle before and after completion of the therapy.Patients eligible for the study after the placebo period received either tiapamil 450 mg b.i.d. or atenolol 100 mg daily. Both drugs lowered systolic and diastolic blood pressure significantly. After 12 weeks of therapy, supine blood pressure in the tiapamil group fell from 167/104 mmHg to 154/91 mmHg (p<0.005), and in the atenolol group from 166/102 mmHg to 151/89 mmHg (p<0.005). A satisfactory reduction in diastolic blood pressure, defined as a reduction of more than 10 mmHg and/or values below or equal to 90 mmHg at the end of the study, was achieved in 29 of 35 patients in the tiapamil group and in 27 of 37 in the atenolol group. No changes in heart rate were observed in the tiapamil group, whereas there was a significant fall in heart rate in the atenolol group. The maximal exercise workload tolerated increased equally in both groups, from 135 to 147 watts. No changes in laboratory parameters were observed.Tiapamil seems to be an effective and safe drug in the treatment of mild to moderate hypertension and in this respect is comparable to atenolol.     

Different apoptotic pathways are induced from various intracellular sites by tetraphenylporphyrins and light.

The induction of apoptosis from different intracellular sites was studied by exposing V79 Chinese hamster fibroblasts to photodynamic therapy (PDT) with various porphyrins and light. The effects of two lipophilic, intracellular membrane-localized porphyrins, tetra(3-hydroxyphenyl)porphyrin (3THPP) and Photofrin, were compared with that of two sulphonated meso-tetraphenylporphines (TPPS2a and TPPS4), which are taken up into lysosomes by endocytosis. Apoptotic fractions induced by the various dyes and light were quantified by flow cytometry using the terminal deoxynucleotidyl transferase (TdT) assay. Cell fragmentation was measured in parallel, while the nuclear morphology of apoptotic cells was studied by fluorescence microscopy. Different kinetics were found for the induction of DNA strand breaks characteristic of apoptotic cells. PDT-induced damage to membranes resulted in an increasing number of apoptotic cells for about 12 h after PDT After damage to lysosomes, apoptotic cells were not detected until more than 12 h after PDT. Furthermore, apoptotic bodies were not observed after PDT-induced damage to intracellular membranes, whereas apoptosis induced from lysosomal sites was characterized by extensive cell fragmentation. Cell fragmentation occurred in combination with or in the absence of nuclear fragmentation. The results support the idea that the degradation phase of apoptosis can consist of a sequence of independent steps rather than a common final pathway.