Diffusion-weighted spectroscopy: a novel approach to determine macromolecule resonances in short-echo time 1H-MRS.

Quantification of short-echo time proton magnetic resonance spectroscopy results in >18 metabolite concentrations (neurochemical profile). Their quantification accuracy depends on the assessment of the contribution of macromolecule (MM) resonances, previously experimentally achieved by exploiting the several fold difference in T(1). To minimize effects of heterogeneities in metabolites T(1), the aim of the study was to assess MM signal contributions by combining inversion recovery (IR) and diffusion-weighted proton spectroscopy at high-magnetic field (14.1 T) and short echo time (= 8 msec) in the rat brain. IR combined with diffusion weighting experiments (with δ/Δ = 1.5/200 msec and b-value = 11.8 msec/µm(2)) showed that the metabolite nulled spectrum (inversion time = 740 msec) was affected by residuals attributed to creatine, inositol, taurine, choline, N-acetylaspartate as well as glutamine and glutamate. While the metabolite residuals were significantly attenuated by 50%, the MM signals were almost not affected (< 8%). The combination of metabolite-nulled IR spectra with diffusion weighting allows a specific characterization of MM resonances with minimal metabolite signal contributions and is expected to lead to a more precise quantification of the neurochemical profile.

Prospective pilot intervention study to prevent medication errors in drugs administered to children by mouth or gastric tube: a programme for nurses, physicians and parents.

BACKGROUND: Drug administration in children is an error-prone task for nurses and parents because individual dose adjustment is often necessary, and suitable formulations for children are frequently lacking. Hence, in the absence of measures for their prevention, medication errors are likely to occur. OBJECTIVE: To assess the error prevalence in drug administration by mouth or gastric tube before and after implementing a programme for quality improvement for nurses and parents. DESIGN, SETTING AND PARTICIPANTS: Prospective, two-period cohort intervention study on a paediatric neurology ward of a university hospital where drug administration procedures of nurses and parents were consecutively monitored during the routine drug administration hours. MAIN OUTCOMES MEASURE: Prevalence of administration errors before and after implementing instructions for appropriate drug administration, and a teaching and training programme supported by information pamphlets. RESULTS: Altogether, 1164 predefined administration tasks were assessed, 675 before and 489 after the intervention. Of these, 95.7% (after the INTERVENTION: 92.6%) were performed by nurses. Errors addressed by the intervention were reduced from 261/646 tasks (40.4%) to 36/453 (7.9%, p<0.001) in nurses and from 28/29 (96.6%) to 2/36 (5.6%, p<0.001) in parents. Errors in predefined categories concerning tablet dissolution, tablet storage, oral liquids, tablet splitting, administration by gastric tube and others were all considerably less frequent after the intervention (each p<0.001). CONCLUSION: Errors of drug administration by mouth and gastric tube represent a considerable and often neglected drug-related problem in paediatric inpatients. Targeted quality-improvement programmes can substantially and rapidly reduce error prevalence. Appropriate teaching and training of both nurses and parents supported by pamphlets was a highly efficient way to reduce error prevalence.

Lithium decreases secretion of Abeta1-42 and C-truncated species Abeta1-37/38/39/40 in chicken telencephalic cultures but specifically increases intracellular Abeta1-38.

We studied endogenous amyloid precursor protein (APP) processing and amyloid beta (Abeta) peptide formation in primary chicken telencephalic neurons, because their Abeta peptide sequence is identical to humans. As detected by quantitative Abeta-SDS-PAGE/immunoblot, Abeta peptides 1-40/42 and three additional C-truncated species, namely Abeta1-37/38/39 were regularly released into the supernatant. The highly conserved Abeta quintet strongly resembles the pattern of Abeta peptides found in human cerebrospinal fluid. Furthermore, the C-terminally shorter Abeta peptides 1-33/34 could be readily detected. Recent evidence indicates that lithium specifically inhibits secretion of the amyloidogenic Abeta1-42 peptide in cultured permanent cells transfected with human APP. We therefore investigated the effect of lithium on Abeta peptide secretion as well as intracellular Abeta peptides in our untransfected primary cell culture system. Our data shows that lithium leads to a dose-dependent reduction of Abeta1-37/38/39/40/42 secretion. Surprisingly, intracellular analysis revealed that lithium specifically increases a band comigrating with synthetic Abeta1-38 while Abeta1-40 and Abeta1-42 remained almost unaffected. These results demonstrate for the first time that lithium treatment decreases Abeta peptide secretion in primary chicken neuronal cells but specifically elevates intracellular Abeta1-38. Therefore, we conclude that there are two independent mechanisms of lithium in intra- and extracellular Abeta peptide production.

Venlafaxine in the treatment of premenstrual dysphoric disorder.

OBJECTIVE: To evaluate the efficacy and safety of venlafaxine, a new-generation antidepressant that selectively inhibits serotonin and norepinephrine reuptake, in the treatment of premenstrual dysphoric disorder (PMDD). METHOD: We conducted a randomized, double-blind, placebo-controlled, parallel-group, flexible-dose trial. After three screening cycles, including a single-blind placebo cycle, 164 women were randomly assigned to double-blind treatment with venlafaxine (50-200 mg/day) or placebo for four menstrual cycles. Primary outcome measures were the total premenstrual symptom scores as assessed by a daily symptom report (DSR) and the Hamilton Rating Scale for Depression. RESULTS: Venlafaxine was significantly more effective than placebo in reducing PMDD symptoms as assessed by DSR scores (P <.001 for last observation carried forward and observed analyses). Sixty percent of venlafaxine versus 35% of placebo subjects improved >50% (P =.003). Forty-three percent of venlafaxine subjects versus 25% of placebo subjects experienced symptom remission, defined as reduction of DSR scores to the postmenstrual level (P =.034). Venlafaxine treatment was significantly better than placebo for all statistically derived DSR factors (mood, function, pain, and physical symptoms). Improvement was relatively swift, with approximately 80% symptom reduction in the first treatment cycle. Mean venlafaxine doses ranged from 50 mg/day in the first treatment cycle to 130 mg/day in the fourth treatment cycle. Adverse events such as nausea, insomnia, and dizziness were mild and transient. CONCLUSIONS: Venlafaxine is significantly more efficacious than placebo for PMDD treatment. Response to treatment can occur in the first treatment cycle, and venlafaxine is well tolerated. Further studies are needed to evaluate the potential of intermittent (luteal phase) dosing for this cyclic disorder and the efficacy of long-term maintenance treatment with venlafaxine.

Zalospirone in major depression: a placebo-controlled multicenter study.

Compounds active at the serotonin (5-HT)1A receptor (mostly azapirones) have shown some evidence of antidepressant effect. We report here the results of an antidepressant trial with zalospirone, a novel cyclic imide with 5-HT1A partial agonist activity. Two hundred eighty-seven outpatients (mean age 44 years, 55% men, 45% nonfertile women) who met criteria for unipolar major depression with a minimum 21-item Hamilton Rating Scale for Depression (HAM-D) score of 20 were randomly assigned to receive 6 weeks of double-blind treatment with either placebo or one of three fixed doses of zalospirone (6, 15, or 45 mg/day), administered three times daily. The high dose (45 mg) of zalospirone produced a significant antidepressant effect compared with placebo from week 2 on with mean improvement (change from baseline) in HAM-D total score of 12.8 versus 8.4 (p < 0.05) at week 6. Clinical improvement with the high dose of zalospirone was consistent across all outcome measures, however, only in the observed cases and not the last-observation-carried-forward analyses. Improvement with the 6-mg or 15-mg doses was greater than that with placebo, but not significantly so, suggesting a dose-response effect. Although the 45-mg dose of zalospirone seemed to have significant antidepressant efficacy, it was not well tolerated. Dizziness and nausea were noted in almost half of the patients, and by week six, 51% of patients in the high-dose group had dropped out. Whether or not tolerance to this high dose might be improved by gradual drug titration, only future research can answer.

[A case of retroperitoneal leiomyosarcoma. Considerations]. / Su un caso di leiomiosarcoma retroperitoneale. Considerazioni.

A case of retroperitoneal leiomyosarcoma is reported. The retroperitoneal localization is quite unusual and early diagnosis is really difficult. Only operation can offer any chance for cure of this neoplasm and radiotherapy and chemotherapy can be very useful. Tumor size and location are the major prognostic factors.

Expression of the E. coli nadB gene and characterization of the gene product L-aspartate oxidase.

Quinolinic acid is synthesized in E. coli by the enzymes L-aspartate oxidase and quinolinate synthase A, the genes of which are named nadB and nadA. In our previous work we cloned and characterized the two genes (Flachmann, R., Kunz, N., Seifert, J., Gütlich, M., Wientjes, F.J., Läufer, A. & Gassen, H.G. (1988) Eur. J. Biochem. 175, 221-228). Here we report on the expression of the nadB gene under control of the inducible left promoter of the bacteriophage lambda. The yield of the active gene product L-aspartate oxidase was enhanced up to 20% of the soluble cell protein. The enzyme was purified to homogeneity in a three-step procedure and the reading frame of the L-aspartate oxidase gene was confirmed by Edman degradation of five cyanogen bromide peptides. L-Aspartate oxidase shows no classical Michaelis-Menten behaviour but is subject to a substrate inactivation. The apparent Km values were different for substrate concentrations below and above 1mM and were determined to 0.5 mM and 4.1mM, respectively. The active form of the enzyme is a monomer of 60,284 Da and contains one molecule of FAD and nine cysteine residues, four of which built up two disulfide bonds. The isoelectric point of the protein was determined to be at pH 5.6. Chemical modifications of the enzyme showed that at least one tyrosine and one histidine residue are essential for enzyme activity. The coenzyme-binding domain is located in the amino-terminal part of the polypeptide chain as revealed by a sequence comparison to other dinucleotide binding enzymes. Furthermore, there is evidence for a relationship to fumarate reductase and succinate dehydrogenase of E. coli.

Molecular biology of pyridine nucleotide biosynthesis in Escherichia coli. Cloning and characterization of quinolinate synthesis genes nadA and nadB.

The two genes, nadA and nadB, responsible for quinolinate biosynthesis from aspartate and dihydroxyacetone phosphate in Escherichia coli were cloned and characterized. Quinolinate (pyridine-2,3-dicarboxylate) is the biosynthetic precursor of the pyridine ring of NAD. Gene nadA was identified by complementation in three different nadA mutant strains. Sequence analysis provided an 840-bp open reading frame coding for a 31,555-Da protein. Gene nadB was identified by complementation in a nadB mutant strain and by the L-aspartate oxidase activity of its gene product. Sequence analysis showed a 1620-bp open reading frame coding for a 60,306-Da protein. For both genes, promoter regions and ribosomal binding sites were assigned by comparison to consensus sequences. The nadB gene product, L-aspartate oxidase, was purified to homogeneity and the N-terminal sequence of 19 amino acids was determined. The enzyme was shown to be specific for L-aspartate. High-copy-number vectors, carrying either gene nadA, nadB or nadA + nadB, increased quinolinate production 1.5-fold, 2.0-fold and 15-fold respectively. Both gene products seem to be equally rate-limiting in quinolinate synthesis.

Double-blind placebo-controlled comparison of dezocine and morphine for post-operative pain relief.

Dezocine, a new mixed agonist-antagonist-type opioid analgesic, was compared in a double-blind trial with placebo and 10 mg of morphine in 190 patients with acute postoperative pain. The medications were given intramuscularly. Dezocine was administered at three dose levels (5, 10, and 15 mg). Pain relief scores, sedation, and side effects were recorded at 15, 30, 60, 120 and 240 min after injection. Significantly higher pain relief scores (p less than 0.05) were reported for the groups receiving dezocine 10 and 15 mg than the placebo group at all observation times, except for dezocine 15 mg at four hours. Morphine produced significantly better pain relief than placebo only between the second and fourth hour after administration. Significantly better pain relief was obtained with dezocine (10 and 15 mg) than with morphine during the first hour. The mean four-hour cumulative pain relief scores (TOTPAR) were significantly (p less than 0.05) higher than placebo for all active treatment groups. Side effects were few with no significant differences between the treatment groups. Seventy-nine per cent of the patients in the dezocine 15 mg group, and 73, 68, 58 and 50 per cent respectively, of the patients in the dezocine 10 mg, dezocine 5 mg, morphine 10 mg and placebo group had a satisfactory clinical response. Significantly (p less than 0.05) more patients in the groups receiving dezocine 10 and 15 mg than in the placebo group had a satisfactory clinical response; the difference was not significant for the dezocine 5 mg and morphine 10 mg groups.(ABSTRACT TRUNCATED AT 250 WORDS)

[Global and regional changes of cardiopulmonary blood volume under continuous work load (author's transl)]. / Globale und regionale kardiopulmonale Blutvolumen-Anderungen unter kontinuierlicher Belastung.

The present study describes a method for the continuous determination of global and regional stress-induced alterations of cardiopulmonary blood volumes in normals, trained athletes and patients with latent cardiac insufficiency. In contrast to normals and athletes there is an increase of the total cardiac blood volume in the cardiac patients. There are also significant differences in blood volume changes of the left lung between normals and athletes on the one hand and the cardiac patients on the other. The method is simple and non-hazardous; it permits the observation of the obviously different adaptation of the cardiopulmonary system during exercise in normals, athletes and cardiac patients.