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Biomedical subjects

E Schweizer

Publications and source records attributed to E Schweizer.

At least 73 records · Page 4Linked to original sources

Nefazodone and imipramine in major depression: a placebo-controlled trial.

Nefazodone is a phenylpiperazine antidepressant with 5-HT2 antagonism and 5-HT reuptake inhibition. Two hundred and eighty-three out-patients with a diagnosis of DSM-III-R major depression of at least one-month duration (65% ill for over 6 months), and a mean score of 24 on the 17-item Hamilton Rating Scale for Depression (HRSD), were randomised to treatment with nefazodone, imipramine, or placebo. The double-blind treatment period was 8 weeks in duration. Nefazodone's antidepressant efficacy was comparable with imipramine's, with both drug treatments significantly better than placebo in a variety of outcome measures. For example, after 8 weeks of therapy, 78% of nefazodone and 83% of imipramine but only 55% of placebo patients (P < 0.01) were globally much or very much improved. Nefazodone was better tolerated than imipramine, with fewer drop-outs and a lower incidence of side-effects during treatment.

Adult↗

Comparison of venlafaxine and imipramine in the acute treatment of major depression in outpatients.

BACKGROUND: Venlafaxine is a new phenylethylamine antidepressant that exhibits monoamine reuptake inhibition. The current study evaluates the efficacy of venlafaxine compared to that of imipramine in outpatients suffering from major depression of moderate-to-marked severity. METHOD: We conducted a double-blind, placebo-controlled, 6-week treatment study of 224 outpatients who met DSM-III-R criteria for major depression, and who had a score of at least 20 on the 21-item Hamilton Rating Scale for Depression (HAM-D). Dosage was flexible and administered on a three-times-a-day schedule, with a mean maximum daily dose of 182 mg for venlafaxine and 176 mg for imipramine. RESULTS: For patients completing 6 weeks of treatment with venlafaxine, the HAM-D total score improved by 16.6 +/- 4.9 points. Improvement at 6 weeks was 13.6 +/- 6.3 points for patients treated with imipramine and 10.6 +/- 7.8 points for patients treated with placebo (p < .05 for active drug vs. placebo). Ninety percent of venlafaxine completers were rated as "much" or "very much" improved on the Clinical Global Impression-Improvement scale, compared to 79% treated with imipramine and 53% treated with placebo (p < .05). An endpoint analysis, where the last scores of patients who dropped out were carried forward to subsequent visits, showed significant efficacy only for venlafaxine and not imipramine, probably because of the higher attrition for the latter drug. Overall, both venlafaxine and imipramine were well-tolerated, with venlafaxine having a somewhat lower attrition rate due to adverse effects than imipramine (16% vs. 25%). CONCLUSION: These results, together with those of previously reported studies, suggest that venlafaxine has antidepressant efficacy comparable to that provided by available antidepressants.

Acute Disease↗

Naturally occurring anti-band 3 antibodies bind to protein rather than to carbohydrate on band 3.

Naturally occurring anti-band 3 antibodies were affinity purified from pooled human IgG (Sandoglobulin) (Lutz, H. U., Flepp, R., and Stringaro-Wipf, G. (1984) J. Immunol. 133, 2610-2618). They bound to the major integral membrane protein of human red blood cells and its 55-kDa NH2-terminal chymotryptic fragment but not to the carbohydrate-rich 38-kDa fragment on blots. Likewise, neither an endo-beta-galactosidase nor a neuraminidase treatment of band 3 on intact red cells reduced their binding to the blotted antigen. Lactoferrin (10 micrograms/ml) had no significant effect on their binding to band 3 and to its 55-kDa chymotryptic fragment. Even in the presence of 20 micrograms/ml lactoferrin anti-band 3 antibodies bound specifically to chymotrypsin-pretreated and oxidatively stressed red cells. Thus, naturally occurring anti-band 3 antibodies bind to protein rather than carbohydrate within band 3 protein, irrespectively of whether the antibodies were depleted of anti-idiotypic and other IgG-reactive antibodies or not.

Anion Exchange Protein 1, Erythrocyte↗

Structure and metabolic control of the Yarrowia lipolytica peroxisomal 3-oxoacyl-CoA-thiolase gene.

Using a Yarrowia lipolytica genomic library, several overlapping clones of the peroxisomal 3-oxoacyl-CoA-thiolase gene, POT1, were isolated. The library was prepared in the bacterial expression vector lambda gt11, thus allowing an immunological screening of recombinant bacteriophages with specific antibodies raised against purified peroxisomal thiolase. The isolated POT1 clones hybridized to a 1.4 kb RNA species, which was induced approximately 30-fold when oleate was the carbon source. A 3634-bp segment of the cloned DNA was sequenced. This segment contained, on both strands, three major overlapping open-reading frames of 678, 1122 and 1242 bp. Northern-hybridization analysis showed that only the largest of these reading frames was transcribed. It encodes a protein of 414 amino acids and molecular mass 43.059 kDa. Its deduced amino acid sequence has 30-60% identity and 50-70% sequence similarity when compared to other known thiolases. According to both the amount (68-71%) and location of conserved amino acids, the encoded protein belongs to the peroxisomal rather than the mitochondrial or cytoplasmic class of thiolases. Compared to bacterial and yeast cytosolic thiolases, the POT1 gene product contains a N-terminal extension of 25 amino acids which clearly differs from typical mitochondrial import signals. One of the isolated clones contained, in addition to the POT1 coding sequence, 784 bp of the corresponding 5' flanking region. Nevertheless, it was efficiently expressed in Escherichia coli suggesting the correct recognition of this fungal promoter by the prokaryotic transcriptional and translational machinery. The Y. lipolytica genomic POT1 gene was disrupted by replacing 120 bp of its coding sequence with 2.7 kbp of DNA including the Y. lipolytica LEU2 gene. The resulting delta pot1::LEU2 cells were free of immunologically cross-reacting thiolase. Western-blot analysis showed that the product of the non-disrupted gene had a molecular mass of approximately 42 kDa. This corresponds well to the molecular mass of purified Y. lipolytica peroxisomal thiolase. Disruption of POT1 abolished the ability of Y. lipolytica cells to grow on solid media with oleate as a carbon source. This inability to grow in the presence of oleate suggests both the catabolic function of POT1 and the absence of additional catabolic thiolases in Y. lipolytica. However, the delta pot1::LEU2 cells were unaffected in their ability to elongate externally added tridecanoic acid to its higher-chain-length homologues. Hence, another, POT1-independent and biosynthetic 3-oxoacyl-CoA thiolase must be responsible for this reaction in Y. lipolytica.

Acetyl-CoA C-Acyltransferase↗

Maintenance drug treatment of panic disorder. I. Results of a prospective, placebo-controlled comparison of alprazolam and imipramine.

One hundred six patients diagnosed according to DSM-III as suffering from agoraphobia with panic disorder, panic disorder with limited phobic avoidance, or uncomplicated panic disorder entered an acute 8-week treatment phase. Patients who improved received an additional 6 months' maintenance treatment. Significantly more patients treated with alprazolam than with imipramine hydrochloride or placebo remained in therapy and experienced panic attack and phobia relief during the acute treatment phase. During the maintenance phase, neither tolerance nor daily dose increase was observed. All patients who completed the maintenance phase (27 in the alprazolam group, 11 in the imipramine group, and 10 in the placebo group) were panic free at the end of 8 months of study treatment. Alprazolam therapy was effective and well tolerated at a mean daily dose of 5.7 mg. Imipramine hydrochloride (175 mg/d) also produced significant panic relief but was associated with poor patient acceptance.

Adult↗

Maintenance drug treatment for panic disorder. II. Short- and long-term outcome after drug taper.

Forty-eight patients with panic disorder completing 8 months of maintenance treatment with alprazolam (mean dose, 5.2 mg [n = 27]), imipramine hydrochloride (mean dose, 175 mg [n = 11]), or placebo (mean dose, 8.0 pills [n = 10]) underwent a gradual taper from medication over a 4-week period. A withdrawal syndrome was observed in almost all alprazolam-treated patients but in only a few imipramine- or placebo-treated patients. The clinical worsening of withdrawal symptoms after discontinuation tended to subside over the course of 3 medication-free weeks, but 33% of alprazolam-treated patients were unable to discontinue their medication regimen successfully. Severity of panic attacks at baseline but not daily alprazolam dose appeared as a significant independent predictor of taper difficulty. Forty-nine percent of the total study population continue to receive drug therapy: 82% alprazolam and 18% imipramine. Among patients who received alprazolam during study treatment and at follow-up, the mean daily dose was substantially reduced (6.1 vs 1.6 mg [n = 14]). At follow-up, after 1 year of naturalistic treatment for panic symptoms and combining 8-month completers and study dropouts, there were no significant differences in remission (68% to 71%) or in antipanic medication intake (39% to 56%) at follow-up for the three original treatment groups. However, 8-month study completers compared with study dropouts had a significantly higher remission rate (85% vs 55%).

Adult↗

Antidepressants for the treatment of generalized anxiety disorder. A placebo-controlled comparison of imipramine, trazodone, and diazepam.

OBJECTIVE: The current study examines whether antidepressants, contrary to current thinking, are safe and effective treatments for generalized anxiety disorder (GAD) not complicated by depression or panic disorder. DESIGN: Randomized, double-blind, placebo-controlled, flexible-dose, 8-week treatment study comparing imipramine hydrochloride (mean maximum daily dose, 143 mg), trazodone hydrochloride (255 mg), and diazepam (26 mg). PATIENTS: Two hundred thirty patients with a DSM-III diagnosis of GAD in whom major depression and panic disorder has been excluded, and who had a Hamilton Anxiety Scale total score of at least 18. SETTING: Seventy-five percent of patients were treated in family practice settings in the community, with the remainder treated in psychiatric practices, either academic or private. RESULTS: Patients treated with diazepam showed the most improvement in anxiety ratings during the first 2 weeks of treatment, with somatic symptoms being most responsive. From week 3 through week 8 trazodone achieved comparable, and imipramine somewhat better, anxiolytic efficacy when compared with diazepam, with psychic symptoms of tension, apprehension, and worry being more responsive to the antidepressants. Among completers, moderate to marked improvement was reported by 73% of patients treated with imipramine, 69% of patients treated with trazodone, 66% of patients treated with diazepam, but only 47% of patients treated with placebo. Overall, patients treated with antidepressants reported a higher rate of adverse effects than diazepam-treated patients, but attention rates were the same across all treatments. CONCLUSIONS: The results of the study need replication, but suggest a potentially important role for antidepressants, particularly imipramine, in patients suffering from GAD.

Adult↗

Double-blind, placebo-controlled study of a once-a-day, sustained-release preparation of alprazolam for the treatment of panic disorder.

OBJECTIVE: The goals of this study were to assess the antipanic efficacy of a new, sustained-release formulation of alprazolam and to assess the safety and tolerability of once-a-day administration of 1-10 mg of sustained-release alprazolam. METHOD: One hundred ninety-four patients with diagnosis of agoraphobia with panic attacks or panic disorder with limited phobic avoidance underwent a 1-week placebo washout before being randomly assigned to groups receiving 8 weeks of double-blind treatment with either sustained-release alprazolam or placebo. RESULTS: There was a significant treatment effect favoring sustained-release alprazolam (highest mean dose = 4.7 mg/day) across almost all measures of anxiety, panic, and phobic avoidance, despite a significantly higher dropout rate in patients receiving placebo. Eighty-five percent of the patients treated with sustained-release alprazolam, compared with 61% of the patients given placebo, reported complete blockade of panic attacks by the end of 6 weeks of treatment. Sedation was the most commonly reported adverse effect. Discontinuation of sustained-release alprazolam was associated with moderate but transient levels of distress in 48% of the patients; discontinuation of placebo led to distress in only 10% of the patients. Nonetheless, there was no difference in the proportion of patients who were able to remain off the study drug for at least 2 weeks. CONCLUSIONS: These results suggest that sustained-release alprazolam is highly effective in the acute treatment of panic disorder at doses comparable to those in the originally marketed compressed tablet of alprazolam. The medication was well tolerated but showed rebound effects during a rapid drug taper after 6 weeks of treatment.

Administration, Oral↗

A double-blind, placebo-controlled study comparing the efficacy and safety of ipsapirone versus lorazepam in patients with generalized anxiety disorder: a prospective multicenter trial.

This multicenter, double-blind, placebo-controlled, randomized study compared the efficacy, safety, and tolerability of ipsapirone (an azapirone anxiolytic) at daily dose levels of 10.0 to 30.0 mg with a daily dose of 2.0 to 6.0 mg of lorazepam (a benzodiazepine) or placebo when given to outpatients with generalized anxiety disorder (GAD) of moderate or greater severity. A total of 317 outpatients with a primary diagnosis of GAD according to DSM-III criteria (at least 1 month's duration) were randomized. Study entry criteria at the time of screening and at baseline included a Hamilton Rating Scale for Anxiety (HAM-A) score of 18 or more, a Covi Anxiety Scale score of 8 or more, and a Raskin Depression Scale score of 7 or less. The study design consisted of a 1-week, single-blind placebo evaluation, a 4-week, double-blind acute treatment period, and a 4-week extension period, followed by a 2-week, single-blind placebo withdrawal period. Efficacy was measured by changes in the HAM-A and Clinical Global Impression Scale and by evaluations of the Hamilton Rating Scale for Depression and Zung-Anxiety Self-Rating scale. The Raskin and Covi scales were performed at screening and baseline only. Withdrawal reactions were assessed during the withdrawal period by the Physician Withdrawal Checklist and by a patient self-rating checklist. Two-hundred sixty-three patients were valid for the analysis of efficacy in the ipsapirone (N = 87), lorazepam (N = 89), and placebo (N = 87) groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The treatment of generalized anxiety disorder in patients with depressive symptomatology.

Concomitant depressive symptoms occur in at least 50% of patients with a primary diagnosis of generalized anxiety disorder (GAD). The authors review the treatment implications of the presence of concomitant depressive symptoms. First considered is the extent to which traditional benzodiazepines, because of their suggested depressogenic liability, are indicated or contraindicated for such patients and the possible differential therapeutic advantage of triazolobenzodiazepines, which have shown preliminary antidepressant effect. Second, the role of tricyclic antidepressants in the treatment of GAD is reviewed. A large body of literature, mostly from the 1970s, has found benefit for the tricyclics in mixed anxiety-depression. Two studies published in the 1980s found that patients suffering from a primary anxiety diagnosis but with subsyndromic levels of depression benefited from treatment with tricyclic antidepressants. The authors also review the role of the azapirones, most notably buspirone, in the treatment of GAD complicated by depressive symptoms. Evidence for its efficacy in this population comes from both retrospective analysis of previous GAD treatment studies, as well as a recent prospective study of depression with concomitant GAD.

Antidepressive Agents, Tricyclic↗

Regulatory gene INO4 of yeast phospholipid biosynthesis is positively autoregulated and functions as a transactivator of fatty acid synthase genes FAS1 and FAS2 from Saccharomyces cerevisiae.

The sequence motif 5' TYTTCACATGY 3' functions as an upstream activation site common to both yeast fatty acid synthase genes, FAS1 and FAS2. In addition, this UASFAS element is shared by all so far characterized genes of yeast phospholipid biosynthesis. We have investigated the influence of a functional INO4 gene previously described as a regulator of inositol biosynthesis on the expression of FAS1 and FAS2. In a delta ino4 null allele strain, both genes are expressed at only 50% of wild type level. Using individual UASFAS sequence motifs inserted into a heterologous test system, a drastic decrease of reporter gene expression to 2-10% of the wild type reference was observed in the delta ino4 mutant. In gel retardation assays, the protein-DNA complex involving the previously described FAS binding factor 1, Fbf1, was absent when using a protein extract from the delta ino4 mutant. On the other hand, this signal was enhanced with an extract from cells grown under conditions of inositol/choline derepression. Subsequent experiments demonstrated that INO4 expression is itself affected by phospholipid precursors, mediated by an UASFAS element in the INO4 upstream region. Thus, in addition of being an activator of phospholipid biosynthetic genes, INO4 is also subject to a positive autoregulatory loop in its own biosynthesis.

Base Sequence↗

Differential proteolytic sensitivity of yeast fatty acid synthetase subunits alpha and beta contributing to a balanced ratio of both fatty acid synthetase components.

The Saccharomyces cerevisiae genes FAS1 and FAS2 encoding the beta and alpha subunit of yeast fatty acid synthetase (FAS), respectively, were individually deleted by one-step gene disruption. Northern blot analysis of RNA from the resulting fas null allele mutants indicated that deletion of FAS2 did not influence the transcription of FAS1, while FAS2 transcription was significantly reduced in the delta fas1 strain. These data suggest an activating role of subunit beta on FAS2 gene expression or, alternatively, a repression of FAS2 by an excess of its own gene product. Compared to the intact alpha 6 beta 6 complex, the individual FAS subunits synthesized in the delta fas1 or delta fas2 strains exhibit a considerably increased sensitivity towards the proteinases present in the yeast cell homogenate. Using yeast mutants specifically defective in the vacuolar proteinases yscA (PRA1/ PEP4 gene product) and/or yscB (PRB1 gene product), it was shown that in vitro, subunit alpha is efficiently degraded by proteinase yscA while for degradation of subunit beta, the combined action of proteinases yscA and yscB is necessary. In vivo, besides the vacuolar proteinases, an additional proteolytic activity specifically affecting free FAS subunit alpha becomes increasingly apparent in cells entering the stationary growth phase. In contrast, under similar conditions uncomplexed FAS subunit beta is stable in strains lacking the vacuolar proteinases yscA and yscB. The reduced FAS subunit levels, at the stationary phase, were independent of the corresponding FAS transcript concentrations. Thus, differential degradation pathways are obviously removing an excess of either FAS subunit, at least under starvation conditions. A combination of both regulation of FAS gene expression and proteolysis of free FAS polypeptides may therefore explain the equimolar amounts of both FAS subunits observed in yeast wild-type cells.

Blotting, Northern↗